This plugin having trouble in a multisite set up

This plugin seems to be causing our server to hang up when used in a multisite environment on a Virtual Server:

[error] [client 96.235.16.166] PHP Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 523800 bytes) in /Library/WebServer/Documents/dev8/wp-includes/wp-db.php on line 1458, referer: http://www.facebook.com/l.php?u=http%3A%2F%2Fdev8.pharmacy.pitt.edu%2Fepittpharmacy%2F&h=5AQHZl3kmAQGPd7mKz_P834NNZ7CQP-gq4AVhQh22Rg_8wA&enc=AZMqvOtwpPkl2lP0CMZL-9pgnZLXUEKC26lkmbUh3r2ICZKxwQBbSSQw0RBCOTLiKHhhGbd2yr4mbEeTwWXE3Ck3&s=1

I hade the server admin allocate more memory to the server, but that didn’t seem to affect the issue at all. I’ve used this plugin on other single site set ups with no issue. Any suggestions on alleviating this problem?

THX

http://wordpress.org/extend/plugins/social/