Ultimate SEO URLs errors.

I get some errors today:
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Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home1/ecshinec/public_html/index.php:5) in /home1/ecshinec/public_html/includes/functions/sessions.php on line 108

Notice: Undefined index: seo_urls in /home1/ecshinec/public_html/includes/functions/html_output.php on line 24

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 31457280 bytes) in /home1/ecshinec/public_html/includes/classes/seo.url.php(1068) : eval()'d code on line 21846

Notice: Object of class queryFactoryResult could not be converted to int in Unknown on line 0
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The Fatal error is about the Ultimate SEO URLs, I think.

How could I fix this error?

I reset the SEO part in admin control panel. Looks like the problem has been fixed.

I don't know the exactly reason, but the site works now. Hope it will work from now on.

This is a randomly reoccurring problem for me. A reset of the cache fixes it, but only for a while. The closest thing I have found to a fix may be listed here:

http://www.oscommerce.com/community/contributions,2823

Titled "memory exhausted fix" I read through the fix and the code seems almost identical to what we have in the zen-cart version. I have not tried it yet out of fear that I will only mess up our site more!

If anyone else has experience with this problem/fix please post.