Please Help Me !! Im in Deep Trouble

Hi People..
I Have a really disturbing problem , i have a 3.15 Mikrotik RouterOs Working on a P4 2GBRAM 160SATA H.D PC
its works good and all interface are read…the only problem that i have is it keeps on freezing on me after running for a while
i have like 15 users only and its just goes dead .. no login page no nothin.
i thought maybe its alot of pressure on it so i disabled caching and it still freezez
i installed a new windows server 2003 server in the network to work as a DHCP server so ican disable DHCP on the mikrotik server so i can take off some more pressure..
and still doesnt work…
what should i do…
i changed swiches – changed PC’s to an AMD PC
nothin nothin nothin
Plzzzzzzzz Help.
thanks

Please don’t cross post!

Run a RAM test to see if the RAM is the culprit. Or, just swap out the RAM