I'm getting the following error when I run my code:

"Unhandled exception at 0x30023861 (nspr4.dll) in PROC.exe: 0xC0000005: Access violation reading location 0x000000e4"

This error only appears when I step through the code (disassembly) using the debugger. The error pops up on the execution of a PR_JoinThread() function. Any idea what might be causing the error and how it could be fixed?