I faced same problem.

What's more worrisome is "Qt: Could not initialize OLE: warning can lead to other issues. Copying to clipboard fails after this warnings, giving error:
"QClipboard::setMimeData: Failed to set data on clipboard".

Workaround is to make the managed code library as dll instead of lib. As long as your qt application does not see the managed code at link time, it is OK.

Regards,

Pankaj