JFYI, I tried to build from scratch qtcontribs with newer versions of MinGW and Qt.
Application Internal Error - C:\SVN\harbour\bin\win\mingw\hbide.exe
Terminated at: 2012.10.10 10:39:51
Unrecoverable error 6005: Exception error:
Exception Code:C0000005
Exception Address:6E0DE193
EAX:011015F8 EBX:009BA037 ECX:77293CC3 EDX:01100174
ESI:009FF8FF EDI:00000007 EBP:0028FDC8
CS:EIP:0023:6E0DE193 SS:ESP:002B:0028FDA0
DS:002B ES:002B FS:0053 GS:002B
Flags:00010202
CS:EIP: 89 03 85 C0 74 2F C7 00 00 00 00 00 89 78 08 89
SS:ESP: 0000001B 009B9127 00500000 00000AFA 0038584C 00002BE8 0082DE00 0028FDEC 6E0DE144 009FF294 0082DE00 0043D82A 009BA037 009FF8FF 009FF294 0043407B
C stack:
EIP: EBP: Frame: OldEBP, RetAddr, Params...
6E0DE193 0028FDC8 0082DE00 0043D82A 009BA037 009FF8FF 009FF294 0043407B 009B9127 00000001 00000002 0038313C
0043D82A 0082DE00 009FF8F4 00000201 005D37A0 0033D0C4 009FF8FF 00000081 00000000 0033D0DC 009FF907 00000001
Modules:
0x00400000 0x00798000 C:\SVN\harbour\bin\win\mingw\hbide.exe
0x77260000 0x00180000 C:\Windows\SysWOW64\ntdll.dll
0x74A40000 0x00110000 C:\Windows\syswow64\kernel32.dll
0x752C0000 0x00046000 C:\Windows\syswow64\KERNELBASE.dll
0x74B60000 0x000AC000 C:\Windows\syswow64\msvcrt.dll
0x75040000 0x00100000 C:\Windows\syswow64\USER32.dll
0x75140000 0x00090000 C:\Windows\syswow64\GDI32.dll
0x76700000 0x0000A000 C:\Windows\syswow64\LPK.dll
0x74CD0000 0x0009D000 C:\Windows\syswow64\USP10.dll
0x751D0000 0x000A0000 C:\Windows\syswow64\ADVAPI32.dll
0x74FF0000 0x00019000 C:\Windows\SysWOW64\sechost.dll
0x768B0000 0x000F0000 C:\Windows\syswow64\RPCRT4.dll
0x74940000 0x00060000 C:\Windows\syswow64\SspiCli.dll
0x74930000 0x0000C000 C:\Windows\syswow64\CRYPTBASE.dll
0x6E0C0000 0x002C2000 C:\SVN\harbour\bin\win\mingw\QtCore4.dll
0x6E940000 0x00010000 C:\SVN\harbour\bin\win\mingw\libgcc_s_dw2-1.dll
0x6FBC0000 0x00007000 C:\SVN\harbour\bin\win\mingw\mingwm10.dll
0x756C0000 0x0015C000 C:\Windows\syswow64\OLE32.dll
0x766C0000 0x00035000 C:\Windows\syswow64\WS2_32.DLL
0x74B50000 0x00006000 C:\Windows\syswow64\NSI.dll
0x67700000 0x009B8000 C:\SVN\harbour\bin\win\mingw\QtGui4.dll
0x76620000 0x0007B000 C:\Windows\syswow64\COMDLG32.DLL
0x74C10000 0x00057000 C:\Windows\syswow64\SHLWAPI.dll
0x743F0000 0x00084000 C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_5.82.7601.17514_none_ec83dffa859149af\COMCTL32.dll
0x758B0000 0x00C4A000 C:\Windows\syswow64\SHELL32.dll
0x74C70000 0x00060000 C:\Windows\syswow64\IMM32.DLL
0x755F0000 0x000CC000 C:\Windows\syswow64\MSCTF.dll
0x749A0000 0x0008F000 C:\Windows\syswow64\OLEAUT32.DLL
0x74370000 0x00032000 C:\Windows\system32\WINMM.DLL
0x73120000 0x00051000 C:\Windows\system32\WINSPOOL.DRV
I tried with Qt 4.8.3 and MinGW 4.7.2 (obviously dw2).