Typical problem with a least privileged install
If you are keeping with best practices and doing any type of install where security is important (shouldn't it always be) then you have probably done a least privileged install. Probably using these instructions Least-privilege administration requirements when using domain user accounts.
One of the challenges of this type of install is things don't always work as expected. Take for example the RADEditor for SharePoint 2007. This handy little tool allows cross-browser rich text edit. Huh? These lets your users with FireFox (or the other 2nd tier browsers) go from an experience like this when editing a wiki
To something very similar to what the Internet Explorer users see
That is pretty cool huh?
The way it works is you download their WSS Solutions Package (WSP) and deploy it to your web application. Then you have a feature named Use RadEditor to edit List items available at the Web (single site) level. The first time you activate the feature it attempts to copy RadEditorList.ascx from c:\program files\common files\Microsoft Shared\web server extensions\12\Template\Features\RadEditorFeature\ to c:\program files\common files\Microsoft Shared\web server extensions\12\Template\ControlTemplates. The only problem is it requires administrator rights on the server to move the file. And the account that it is attempting to use to move the file is your application pool account. And if you did a "proper" install that account does not have local administrator permissions on the SharePoint Server.
The problem? You never get an error message to let you know the copy failed. :( So you are left guessing. Once you discover this problem simply move the file over to the proper directory. Now do an IISReset.exe and your non-IE users will be happy.
The main reason I bring up this issue is it is very common. Often when you do a least privileged install you will find little issues like this, so be prepared.
Shane – SharePoint Help