With Geeklog 1.8.0 Google Chrome seems to be working fine for me now under the professional theme with the authentication issue. I am not sure what changed
The Purepro theme works fine in IE9.
The Purepro theme still has problems under FireFox and Google Chrome. I was looking into this a bit and for some reason the token in the code is not the same as in the database. It appears somehow that SEC_createToken gets executed again...
Also if you view the source under FF or GC it seems to request the information from the web server again which updates the tokens so you get different ones again which confused me for a bit.
If I find any more info I will post it.
One of the Geeklog Core Developers.