My Opus Directory 9.5.6 x64 sometimes freezes when I click on a file or a program file in it.
Of course it's a strange behaviour, 'cause 32bit version does not show this problem.
Is there something I could do to resolve it?
It's not a 32-bit vs 64-bit issue. (Lots of people use the 64-bit version fine and you can't have installed the 32-bit version on the same machine you tried the 64-bit version on. It's likely to be something on the 64-bit machine that is conflicting.)
The information in these FAQs should help track down what is causing the freeze:
Maybe I was right: I uninstalled 9.5.6 and installed 9.5.5 and got no problem since 2011.02.13...
Try installing 9.5.6 again; I bet the problem doesn't come back, but if it does that might help locate what's going wrong on your machine.