For the x86 build you tried, you're using a different version of the CRT in Qt compared to the one you're using with Sigil. Essentially, you downloaded the pre-built Qt binaries from Nokia which are built with VS 2008 and then you tried to run-time link them with a Sigil exe built with VS 2010. That won't work. Build Qt from source using the same compiler you will use when building Sigil.
Same thing goes for your x64 build; the Nokia binaries are x86 and you can't link those to an x64 Sigil.
Last edited by Valloric; 12-12-2010 at 10:29 AM.