Device: O2 UK GSM pre
ROM:1.45 upgrade to 2.1,all are fine.

Under 2.1 Sign in also was OK.

But I dont like 2.1,so return 1.45.

Then strange thing is coming:
under 1.45 ,sign in always failed.even cant create new profile.

Somebody said that everytime before doctor device,you should close BackUp to Erase Remote Data. I have tried that,but no effect.

When log in my profile on palm support,can see under "device detail" there is a record:
rom version is 2.1
So i remove that record.But still cant sign in ,or create new.

My Wifi is ok,and I bypass active is success.

So anybody has the same issue?