I just tried the link to "no check browser" thing. No luck. Same problem. I'd like to ask others who are having this issue to scroll down in GMail, go to basic HTML, and see if it tells you you're logged in from another connection or not. And if it's not too much trouble copy and paste what the 'Details' link tells you.

I suspect we're all having the same problem, but maybe not.

Ideally we should get a comparison of everything we have installed too. I have:

Maemo 5 with pr1.2 and stock kernel. No change to partitions, etc.

VGB
VGBA
MyPaint
Opera
Midori
Firefox
Tear (got it after this problem arose)
fMMS
FM Radio
ForecaWeather
Health Check
MaeGirls
Maemo Recorder
XChat IRC
Moodlight
Liquid War
QtIrreco
Wireshark (gotten after this started)
Extra Decoders Support
Ogg Support
Midi Support
Array Theme
Marina Theme
Harmony Theme
Melody Theme
World City Theme
3G/2G/Dual Mode Selection Applet
Bluetooth Dial-Up Networking
Cellular Modem Control Buttons
Flashlight
cpumem-applet
Live Focus
OpenSSH Client and Server
Portrait Keyboard
Recaller
rootsh
Simple Brightness Applet
TuneWiki Desktop Widget

(...holy **** I have more than I tought)
Unless otherwise indicated, I got them before this GMail thing happened. (The only thing I did right before is ran two commands that glitched my x-term into crashing upon "killall hildon-input-method" - they switch the kyboard between the portrait-friendly one and the default.)

Anyway, I have WireShark installed now - but it'll take me day or two to learn my way around enough to figure out what packets to capture, let alone what they mean.