When I start Thunderbird, it works fine for 30 seconds. Then, attempting to click on any email on the list view grid causes a "Not responding" message. This just started yesterday. My profile is 2 GB. I've got about 9000 messages in the program. Disabling Norton AntiVirus doesn't help, nor does running TB in safe mode or running Windows 7 in safe mode with networking. My provider is GMail, and I've got TB set to retrieve in POP mode. It's been running fine for 10 years this way. Nothing that I know of changed yesterday. I was on 45.x and updated to 52.1.1 32-bit after this happened hoping that would fix it. I also rebuilt the global index, and deleted and reinstalled TB. If I run in offline mode, everything is fine. I can pull up any message with no delay. The second I turn it back online however, it started freezing up again. I created a new profile and copied the account settings and the mail folders. The same thing happens now in the new profile. Any ideas?