APC - PHP Cache

[altec_lansing]

Hi,
I installed the Alternate PHP Cache (APC) to reduce page loading time.
The admin interface apc.php works and shows it's caching php files.

But only for about 15s, APC restarts within 10-20s and clears the cache.

I'm on Plesk 11, with Debian 6, Apache2 and Nginx as reverse proxy, i hope someone can help me with that... .

Thanks,
Altec!