Hey Nick,
We can't reproduce this here. Make sure the dll version for both your x86 and x64 version is at least 4.0.9.2. Version 4.0.9.0 had a crashing bug in the x86 version.
If you're still having problems we need more information (because we can't reproduce this here based on the information provided):
1. The version of windows you're using.
2. The language you're using (C/C++ presumably)?.
3. (optional, but useful): Steps to reproduce this. Either example code or something.
4. The exact function you're calling with parameters that casues the "hang" (is it a crash or a hang?)