I've been having a recurring problem with my RaQ4i server at rackshack.net. Every few days, it stops responding to telnet/HTTP, and only ping works.

A reboot fixes the problem, but only temporarily until the next time.

I don't know why this is happening, and the rackshack.net techs haven't been able to figure it out thus far either.

Does anyone have any hunches as to what the problem could be?

Could be running out of RAM and the kernel is just killing processes to free some up. Thats my first inclination.