Here is a self-contained reduced sample of the problem. All you have to do is hover over the btnbmp to see the [ugly] black square that gets drawn around the button:
#include "fivewin.ch"
FUNCTION START()
LOCAL oDlg
DEFINE DIALOG oDlg NAME "TestDlg"
REDEFINE BTNBMP RESOURCE "Find16" ID 200 OF oDlg NOBORDER ;
ACTION MsgInfo("btnbmp" ) TRANSPARENT ;
TOOLTIP "Test BtnBmp"
REDEFINE BUTTONBMP BITMAP "Close16" ;
TEXTRIGHT ;
ID 201 ;
OF oDlg ;
ACTION oDlg:End() ;
TOOLTIP "Remove id image"
ACTIVATE DIALOG oDlg
RETURN NIL
Now the .rc file
CLOSE16 BITMAP
MOVEABLE PURE LOADONCALL DISCARDABLE
LANGUAGE LANG_NEUTRAL, 0
BEGIN
'42 4D 9E 02 00 00 00 00 00 00 36 00 00 00 28 00 '
'00 00 0E 00 00 00 0E 00 00 00 01 00 18 00 00 00 '
'00 00 68 02 00 00 12 0B 00 00 12 0B 00 00 00 00 '
'00 00 00 00 00 00 FF FF FF FF FF FF FE FE FE F6 '
'F6 F7 FD FD FD FF FF FF FF FF FF FF FF FF FF FF '
'FF FD FD FD F5 F5 F6 FE FE FE FF FF FF FF FF FF '
'00 00 FF FF FF FD FD FE CF CF D5 5A 5A A8 D0 D0 '
'D4 FD FD FE FF FF FF FF FF FF FC FC FD C1 C1 CB '
'5F 5E A9 DE DE E4 FE FE FE FF FF FF 00 00 FE FE '
'FE CD CD D4 3E 3D C1 39 35 EE 51 4F C2 D2 D2 D8 '
'FD FD FE FC FC FD C0 C0 C9 4D 4A CE 3B 38 EE 4A '
'4A B6 DE DE E4 FE FE FE 00 00 FC FC FD 5B 5B AF '
'0E 0D EB 2A 28 F4 45 41 F2 50 4F BF D1 D1 D6 BF '
'BF CA 4D 4A CD 49 45 F4 2D 2A F5 13 12 E8 77 77 '
'B7 FE FE FE 00 00 FF FF FF E2 E2 EE 3C 3C C8 13 '
'13 EF 2A 27 F4 39 36 F1 46 46 C4 42 40 D0 3C 38 '
'F3 2B 29 F4 16 15 EE 4D 4D C5 ED ED F7 FF FF FF '
'00 00 FF FF FF FF FF FF E0 E0 ED 3C 3B CA 0E 0D '
'EF 18 16 F4 1E 1C F3 20 1E F3 18 17 F3 10 0F ED '
'4F 4F CB EC EC F7 FF FF FF FF FF FF 00 00 FF FF '
'FF FF FF FF FF FF FF DA DA E7 32 32 CA 02 03 F2 '
'04 03 F3 03 03 F2 04 04 F1 46 46 BC EB EB F5 FF '
'FF FF FF FF FF FF FF FF 00 00 FF FF FF FF FF FF '
'FC FC FD B8 B8 C4 27 27 D2 01 01 F2 01 01 F3 00 '
'00 F2 02 02 F1 38 38 C3 CF CF D5 FD FD FE FF FF '
'FF FF FF FF 00 00 FF FF FF FC FC FD BD BD C6 3B '
'3B CD 1E 1E F1 21 21 F5 23 23 F3 23 23 F3 21 21 '
'F4 22 22 F0 48 48 BF D2 D2 D8 FD FD FE FF FF FF '
'00 00 FE FE FE C3 C3 CD 53 53 CF 4B 4B F4 4B 4B '
'F6 4C 4C F3 5C 5C C9 55 55 CD 4B 4B F3 4B 4B F6 '
'4C 4C F2 57 57 C0 D6 D6 DB FD FD FE 00 00 FC FC '
'FD 75 75 B9 6F 6F F2 6D 6D F8 6E 6E F4 6A 6A C3 '
'EC EC F6 E2 E2 F1 66 66 CC 6E 6E F5 6C 6C F7 6F '
'6F F1 81 81 B3 FD FD FE 00 00 FF FF FF EE EE F4 '
'77 77 CA 8E 8E F5 77 77 C9 F0 F0 F7 FF FF FF FF '
'FF FF E4 E4 EE 75 75 CF 8E 8E F4 7B 7B C2 F5 F5 '
'FA FF FF FF 00 00 FF FF FF FF FF FF F0 F0 F6 91 '
'91 C9 F3 F3 F9 FF FF FF FF FF FF FF FF FF FF FF '
'FF E7 E7 EF 92 92 C6 F7 F7 FA FF FF FF FF FF FF '
'00 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF 00 00 '
END
FIND16 BITMAP
MOVEABLE PURE LOADONCALL DISCARDABLE
LANGUAGE LANG_NEUTRAL, 0
BEGIN
'42 4D 36 03 00 00 00 00 00 00 36 00 00 00 28 00 '
'00 00 10 00 00 00 10 00 00 00 01 00 18 00 00 00 '
'00 00 00 03 00 00 00 00 00 00 00 00 00 00 00 00 '
'00 00 00 00 00 00 FF FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF 91 91 91 88 88 88 8A '
'8A 8A 8A 8A 8A 85 85 85 AD AD AD FF FF FF FF FF '
'FF C8 C8 C8 83 83 83 8A 8A 8A 8A 8A 8A 89 89 89 '
'86 86 86 FC FC FC C0 B9 B8 DA 9F 95 FF DA D7 DD '
'BA B5 A4 79 71 7B 4B 40 61 33 2B FF FF FF FF FF '
'FF 97 64 5D EE BB B2 F3 D3 CF BB 94 8E 83 56 4B '
'7F 49 3F A7 A7 A7 E9 E4 E3 B6 83 7C DE BA B6 BE '
'9D 98 8D 66 5F 6A 3E 34 5F 33 2A FF FF FF FF FF '
'FF 98 66 5F CB 9C 95 D2 B3 AF A0 7D 77 71 47 3E '
'6D 3D 34 C8 C8 C8 FF FF FF B9 8C 84 EB D4 D2 D1 '
'B8 B3 9B 78 72 72 4C 41 64 3D 34 FF FF FF FF FF '
'FF AD 81 76 DA B4 AD E3 CE CC B2 93 8C 7C 57 4D '
'6C 40 38 EC EC EB FF FF FF D6 B4 AA FF FF FF FF '
'FC F5 BE A7 9F 8A 6D 61 74 54 4A FF FF FF FF FF '
'FF D4 AC A2 FF F2 E8 FF FF FF DD CB C4 97 7C 71 '
'77 56 4C FF FF FF FF FF FF A2 88 80 FF FF FF FE '
'F3 ED B9 A1 99 86 68 5C 76 54 4B FF FF FF FF FF '
'FF D0 A7 9D FD EA E1 FF FF FF D8 C4 BC 95 79 6E '
'62 43 39 FF FF FF FF FF FF A2 8D 88 FF FF FF FF '
'FC F6 BD A6 9E 87 69 5E 84 60 55 93 93 93 C2 C2 '
'C2 DC B1 A7 FF F2 E9 FF FF FF DE CB C3 9A 7E 72 '
'4C 34 2D FF FF FF FF FF FF CB BC B9 DD D3 D3 C4 '
'AF A9 94 74 6B 79 56 4B 75 52 48 3A 2D 28 7B 6C '
'69 A7 80 76 C4 A7 9E D4 C5 C4 BB A0 99 96 73 69 '
'7A 6C 6A FF FF FF FF FF FF FF FF FF 79 69 65 E5 '
'CC C3 DF D8 D6 91 81 7A 65 4C 41 32 20 1C 6D 5A '
'56 DF BD B1 E3 DF DB 93 81 79 5A 41 36 2E 1E 19 '
'FF FF FF FF FF FF FF FF FF FF FF FF 98 80 7B FF '
'FF FD FF FF FF C6 AF A5 8D 6E 60 36 23 1E 74 63 '
'5D FF F0 E4 FF FF FF D7 C1 B9 91 72 66 45 30 2B '
'FF FF FF FF FF FF FF FF FF FF FF FF C7 B4 B0 D2 '
'BC B4 C2 B1 AE 95 75 6C 7C 58 4D 39 26 23 53 3F '
'39 CD A9 A0 CC C0 BF B1 93 8D 85 63 58 60 4C 48 '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF B2 '
'99 94 FF FF FF FF F6 F0 96 7A 6C 8E 7E 79 BF AE '
'AB FF FF FF FF FE F8 8F 73 65 81 6C 67 FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF 62 38 30 7A 68 64 3A 20 19 FF FF FF CE C0 '
'BD 77 5F 59 40 26 1D 9B 88 85 FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF D5 CA C7 83 6E 69 7D 65 5F FF FF FF F7 F6 '
'F5 93 7E 78 7B 61 5B FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF '
'FF FF FF FF FF FF '
END
TESTDLG DIALOG 6, 14, 163, 98
STYLE DS_SETFONT |DS_MODALFRAME |WS_OVERLAPPED |WS_VISIBLE |WS_SYSMENU |WS_CAPTION
CAPTION "Test Dlg"
FONT 8, "MS Sans Serif"
LANGUAGE LANG_NEUTRAL, 0
BEGIN
CONTROL "",1001,"BUTTON",BS_GROUPBOX |WS_CHILD |WS_VISIBLE ,3,69,154,23
CONTROL " Close",201,"BUTTON",BS_PUSHBUTTON |BS_VCENTER |BS_CENTER |WS_CHILD |WS_TABSTOP |WS_VISIBLE ,104,75,50,14
CONTROL "",200,"TBtnBmp",WS_CHILD |WS_VISIBLE ,15,11,14,14
END
Perhaps now you can all see what I mean?
Reinaldo.