[Qt-interest] Heap corruption after update to 2009.03

[Info]

Hi,

I've recently updated from Qt 2009.02 to 2009.03 (opensource) and  
found a strange problem and was wondering if anyone else had  
experienced anything similar...

I am getting random heap corruption errors in Windows like "The  
application [MyApp.exe] HEAP: Free Heap block 357ddc0 modified at  
357dde8 after it was freed" at random points in the application.

I'm trying to find a pattern to it and I thought I had found the cause  
in adding/removing QWidgets from a QVBoxLayout but it seems that is  
not the case. I have narrowed it down to having a QMainWindow open. My  
app can run for hours with no problems until I open a QMainWindow,  
then it may run for a few seconds or 5 mins but will crash with the  
error above (usually sooner rather than later). I would expect to see  
this sort of thing if I was loading a DLL built with /MD instead of / 
MDd (as this only happens in debug builds) but I built the source  
using the -debug-and-release flag and I've checked that all the DLLs  
loaded by my app end in 'd4.dll'.

Has anyone else experienced this? Is it possible that QtGuid4.dll is  
using the incorrect version of the CRT? (I've checked the DLL with  
depends.exe and it seems to be linked to MSVCR80D.dll)