I noticed PMS would suddenly stutter or stop altogether starting with version 1.90.0. The first video would normally play OK, but subsequent videos during the same program session would stutter or stop. The log would continually loop with the error "Cannot grow buffer size from 50,000,000 bytes to .... OutOfMemoryError: Java heap space". In addition javaw.exe would grow very large and would not terminate when PMS was closed.
In searching the forum I found a fix that seemed work work:
You need to locate "PMS-x64.bat" in the PS3 Media Server folder and modify the parameter "-Xmx768M" in the SET command to a larger memory value such as "-Xmx1536M" where 1536 is in Mb.
Create a shortcut to PMS-x64.bat and use the shortcut to launch the server rather than the original shortcut. You may also have to change the permissions on the file to allow you to modify it.
I hope this helps if anyone is having the same problem.