Can't establish a reliable connection to the server on Xperia X8

Alright, so there's this Xperia X8 with Android 2.1 (i think) that won't add a google account. The above mentioned error occurs and I can't login to my google account.
I've been looking for a solution to this on the interwebs but all of them requires root so you can edit the hosts file.
Time and timezone is set correctly also.
Since this xperia is all stock and not rooted - what are my options to fix this problem?