two part issue - both resulting in 404 error pages:
1. Certain buttons on tinymce editor (Nextgen gallery and Cforms II) give small 404 error pages.
2. The output of some plugins and scripts like this new one (simple maps) gives a 404 error code (/wp-content/plugins/simplemap/actions/location-process.php)
Actions taken so far: Upgraded to latest wordpress version, installed fresh copies of wp-admin and wp-includes folders, deactivated ALL plugins (except the the one or ones that produce the error in #2 above). But none of this helps.
I installed the same plugin (from #2 above) on two other wordpress installs - one on the same server as the one giving me issues - and it works flawlessly. Additionally, the two other WP installs mentioned aren't having the tinymce issue, either.
Have I missed a troubleshooting step? I hope someone can assist me with this please. :)