[AndreT]

Please ****** how to attach strace to a process (usually you have to install it, on CentOS that would be "yum install strace", then run the server, get its process ID and use "strace -p ID" to attach it - this will output all the data to your ssh console).
GDB needs to be launched (and before that, installed similarly as well) and the server needs to be ran in that interface. But since the SA-MP server itself does not come with debug flags, and neither do a lot of the plugins, I'm unsure about the quality of the information you'll retrieve through gdb (but most likely it'll determine the source of your crash).

Did you doublecheck whether your PAWN scripts are compiled with -d3 for maximal debugging chances with crashdetect?

Also, what would be a good idea is to have your script ready for debugging at any given moment, so everything required to turn on complete debugging is a simple recompile with different precompiler settings (perhaps #define DEBUG and your debug messages check #if defined DEBUG and then print something!). This would also get you closer to the source of the problems.

Do the current logs tell you anything?
Are there any similarities between different server runs in the logs just before the crash?