Originally Posted by JayKindle
Here is an example.
I tried opening a Mobi file that I had converted from PDF.
What program did you use to do the conversion - I have had some similar performance issues as you're having - and I think PDF conversions may have been a factor.
I find that MobiCreator is both the simplest and the best.
It works straight out the box, apart from some folder locations there are no settings to tweak. Its free, development has ceased, so no upgrades to worry about - I've used on XP, Vista and W7. It's never misbehaved.