I can barely keep the mouse in one place without it launching some new application or closing something.

I did a hard reset and restored the Chrome settings to Default.  Power cycled several times.  

What type of computer?
Is this an external mouse or builtin trackpad?
Have you tried a different mouse?

Please also file a feedback report when you see the problem (alt+shift+i).  Respond here once you have done so (along with the answers for #3)!

It is a Samsung Chromebook 3.  The touchpad on the computer is inoperable and I have tried both an optical mouse and a USB mouse.  Thank You.

Update: Samsung and the touchpad vendor are working on this issue.  We'll update here once we know when a fix can be expected.

(for anyone with partner-bug access, see crosbug.com/p/57704)

Hi David - there are changes in M54 Beta channel (8743.69.1) that should fix your problem.  If you don't want to switch channels, M54 will be stable very soon.

Please let us know if this update or the M54 stable update don't help your situation!

Marking as fixed. Please re-open if issue can be reproduced on 54+ stable.