WP 3.0 running slow since upgrade

Have you tried:

– deactivating all plugins to see if this resolves the problem? If this works, re-activate the plugins one by one until you find the problematic plugin(s).

– switching to the default theme to rule out any theme-specific problems?

– resetting the plugins folder by FTP or phpMyAdmin? Sometimes, an apparently inactive plugin can still cause problems.

– increasing the available memory?
https://www.ads-software.com/support/topic/253495#post-1017842

– reviewing https://www.ads-software.com/support/topic/411649

The wp-admin admin function is slow too, so it isn’t the theme (plus I tried the default theme, same problem). I also followed the other troubleshooting steps and haven’t isolated the issue.

I also noticed I get 500 errors when posting or previewing pages.