Comment 2 for bug 315942

Thanks for the bug report. First of all please make sure that you upgrade to the latest version of FireFox. I have 3.0.5+nobinonly-0ubuntu0.8.10.1 installed on my 8.10 and a security advisory (USN-690-1) have also been send out recommending upgrade to above version.

If the problem still persists make sure that you don't have any extensions installed (except Ubuntu Firefox Modifications) and that you have a clean firefox profile. This can be achieved by creating a new user or by removing ~/.mozilla directory. If that solves the problem it was either a bad extension or something in your profile that caused the issue.

If problem still not solved please try to make DNS lookup for www.fi. You can do that by opening a terminal and type 'host www.fi'. I have pasted my output below. If the lookup gives another result it is most likely your ISP's DNS server that causes the issue.

jonas@asterix:~$ host www.fi
www.fi has address 193.93.132.82
www.fi mail is handled by 10 mimas.inet.fi.
www.fi mail is handled by 15 calypso.inet.fi.
www.fi mail is handled by 20 smtp.tele.fi.
www.fi mail is handled by 30 smtp.inet.fi.

Please note that I don't have the issue with www.fi being changed to www.fi.com in firefox.