Finding multithread program error?

[superfury]

How do I find an error in a multithreading program (written in C)? I get an address, but when I put it into psp-addr2line, i get

??
??:0

Anyone knows how to correctly and easily sniff the problem out?

(Have this regularly. Anyone knows how to find a permanent way to sniff this out?)

[Zhuge]

You get an address? The address of what? And what error are you even getting?

[superfury]

An address that (in a non-multithreading app) would be the memory address (linear) of the PC register (in the case of the PSP 0x8XXXXXXX, which should be the address of the instruction in memory). But instead of psp-addr2line giving the function that went wrong, it gives the function that handles the thread itself (which is launched by a kernel function, in this case sceKernelStartThread(...)). Though the problem is a couple of functions deeper (not inline).