Store down - PHP Fatal error: Out of memory in /includes/classes/seo.url.php

[rxalex]

My site has a blank page on the front end but I can access the backend with no problem. I am using 1.3.9h, the error log reads [09-Oct-2011 00:24:38] PHP Fatal error: Out of memory (allocated 52953088) (tried to allocate 79691776 bytes) in /homepages/25/d1600177/htdocs/store/includes/classes/seo.url.php(1131) : eval()'d code on line 87382
in explorer I get HTTP 500 and in firefox its a blank page
The shop worked great for a few months..I contacted host, they said there is plenty of memory - I need some help here my shop is down

[rxalex]

It was the seo module that went bad or something.. turned off Enable SEO cache to save queries? which fixed the issue. Thanks Drbyte for trying to help.