I would boot from the gray DVD that came with your Mac, and run Disk Utility, and Repair Permissions. The free tool OnyX can also repair permissions, without forcing you to boot from another disk.

If you get an error message that you do not have sufficient permissions to update then easiest is to trash the currently installed version to do a clean install of the new version.

• Download a new copy of the Firefox program and save the DMG file to the desktop
• Firefox 4.0.x: http://www.mozilla.com/en-US/firefox/all.html

• Trash the current Firefox application to do a clean (re-)install
• Install the new version that you have downloaded

Your profile data is stored elsewhere in the Firefox Profile Folder, so you won't lose your bookmarks and other personal data.

Er, no gray disk only a chip with the OS on it. I've been through the disk permissions before but that didn't help (I don't think), but I'll try it anyway.

I'd like to trash ver 3.x but I get the same notice and am not allowed to remove it. I'll start by redoing my permissions.

Thanks

I'd like to trash ver 3.x but I get the same notice and am not allowed to remove it. I'll start by redoing my permissions.

OK so how do I delete a post?

You can't. You can edit your post and change its content to something like (deleted) if you want to.

Thanks for letting me know I can't delete a post.

I tried repairing my permissions using the Mac disk utility that on the active OS and it said it did something but no change in how Firefox functions. I'll try and reboot and if no luck there I'll try and see what Apple support has to offer. When I did the last upgrade it took about 6 calls to them and it may have had something to do with the permissions, I really can't remember. If I find a solution I'll be sure to post it.