We are building the Tesseract code with Visual Studio and we've found where some (apparently) compiler optimization bugs are affecting us - definitely with VS2013 Community, but also perhaps with VS2008. Some of your details (x86 but not X64) sound similar - but this is a very "conditional" problem depending on image data, code and sometimes threading.
I solved it for us by adding some #pragma statements to disable optimization for the problematic function.
I reported details in my latest notes for
https://code.google.com/p/tesseract-ocr/issues/detail?id=1496If you're building with VS then my changes are worth a try. Let us know what you find!
-= Rich Taylor