Forum Can't log in?

[محروم.كوم]

I'm trying to log into my forums (just installed) and it accepts my details, thanks me for logging in then takes me back to the page without me being logged in. I've tried using different browsers and three different computers but all have the same problem.
I also can't access the admin cp for the same reason it lets me log in then brings me back to the page asking me to log in again. Its an endless cycle


Any ideas what I'm doing wrong? More importantly how to fix it!?


Thanks,
Sacred __DEFINE_LIKE_SHARE__