I encounter the same kinf of pb with the version 2.5.0, do you have any news about the problem ?
For my case, I use PDF Creator with the COM interface from a Java program
In my java program
The first call ReleaseCom is ok
The second ReleaseCom call is ok
But always at the 3rd call of ReleaseCom, my program is frozen
Al these calls are done from the same main process
But if I call 3 times my java program (so 3 differents process), I have not the problem