Accesslog Crash Problem

My Accesslog Table often (once in two days period) crashes as a result of this problem my server is down. I think connected to the accesslog table crash problem, node_counter and/or watchdog tables also crash. And sometimes cash tables crashes because of this. And as I understood accesslog table crash causes the faults of other tables. We have approximately 10.000 members. We use 40-45gb bandwidth monthly. I have been using Poormanscron Module for one week I still have the problem. I couldn't be able to solve this problem. What will I do or how can I fix it.

Please reply me back asap.

Thank you for your kind responce

My server options:

PHP Version 5.2.5
Apache/2.2.3 (CentOS)
mysql - 5.0.51

Regards,

Sadan
www.cemaat.com