Firefox isn't saving bookmarks

When I try and bookmark something to a subfolder under the "Bookmarks Menue" I click 'bookmark' and then 'done' but when I go look in the sub-folder where it is supposed to be, it isn't there. When I save to the regular "Bookmarks Menue" though then it saves correctly. I thought this was very odd behavior, could this be malware of some sort or is there something wrong with my settings?

Thanks for any feedback, Robert.

 

What version is this?

 

3.6.28

I don't want to upgrade 'cause i like the interface as is and don't want it to look more chrome like where there's no 'Files' 'Edit' 'View' 'History' drop downs...i like those where they are.

 

The menu bar can easily be enabled in later versions of Firefox.