[SOLVED] Can only login in with IE and Firefox, only Chrome

I dont think this is an Atahualpa issue, but am registering it to see if anyone else has encountered it. I run 4 sites, all ATA. Upgraded one to Wordpress 3.0.1. and now cannot login in via IE and Firefox. Only Chrome. Ive done the cookies thing, switched off plugins, tried wp-login. The other V3.0 sites are fine.
When I try IE or Firefox, it simply gives me back an empty login panel. Thing is, if I use the wrong password, IE at least alerts me to that. Site is enablers.co.nz
I cant believe I am the only one to experience it. I logged this on the WP site, and got one reply. Was helpful guy, but no fix.
Has anyone else experienced something similar. I get the feeling this is something very simple, or very deep.
Cheers
Bryan