Stuck on paintbrush tool while trying to use clone stamp.

Hey all,

I'm having a very strange issue with my AE...

I have a lapel mic on an actor I'm trying to clone out, so I open the file, select the 'Cone Stamp' tool, but nothing happens, so I double click on the layer and then it reverts to the paint tool, holding ALT doesn't give me the option to select a clone area and I'm not able to do anything else. No matter what tool I select, it's stuck on paintbrush. If I select the zoom tool and click on the screen, it starts painting. I change to the selection tool (V) and click on the screen, it paints. I literally can't do anything else and have to close the software.

Anyone else seen this before? It's extremely annoying.