Hi timrh, in firefox safe mode do you have the same behavior ? (In safe mode except the extensions, hardware acceleration is also disable, if the issue is here)

also, maybe not related, but you have a user.js file in your profile folder.

The user.js file does not exist by default. If you create the file, forget it, if you have not create the file then delete the User.js file, to see if the problem goes away (some programs create and write in the file also).

thank you

OK. Tried both of thes - removed user.js, and removed all addons (start in Safe Mode. No change. What I DID find is that I can reproduce this simply by sliding left from the bezel on to the touchpad. This seems to be the problem. On this machine that SHOULD display the charms bar. However, it launches the developer tools instead.

Now, for me, that's solved the problem, because I don't really use the Charms bar. So I can disable that gesture. I don't know why it's getting through to FF as I would have thought that should be intercepted by the O/S before it gets there.