Here’s a tip on how to adjust for the additional WordPress memory demands from the guys at We Fix WP

For those of you on shared hosting plans, you may notice that WordPress needs more memory than ever. Perhaps you’ve found that out while you’ve attempted to upgrade to WP 2.8.5. We’ve seen:

• WordPress and/or certain plugin updates hanging
• WordPress and/or some plugins not installing completely
• The the now-popular white screen (in both the dashboard and on the blog itself
• The “WordPress Upgrade Error Allowed Memory Size Exhausted” error
• A fatal error similar to: Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 2354671 bytes) in ../public_html/wordpress/wp-includes/http.php on line 1331

What’s the fix?

To increase the memory limit, add this bit of code to the top of your wp-config.php file:
@ini_set("memory_limit","64M");

If your host doesn’t allow this memory increase, it may be time to migrate to a better performing one.

Other Issues
We have read that certain plugins, such as Google XML Sitemaps and Super Cache (we often recommend using both of these), also needs a bunch of memory. So you’ll need that update to your wp-config.php just to keep those running properly. Finally, it’s also good practice to review all of your plugins and remove any that you no longer need.