I've just purchased a N96 a few days ago (AVAXX). No problems with the firmware updating (I did it via Nseries PC Suite while connected to my laptop, and my laptop was connected online via Wireless LAN).

I've also been able to access and surf the web and check email via WLAN without difficulties or connection problems.

Overall, I'm very pleased with it.

I don't mobitubia on my phone so I'm not sure how it works.

As for .avi files, I think you'll have to convert it to another format before you can play it in your phone. I used the Nseries PC Suite's Video Converter to convert a few .avi movies and they can play very well on the phone. Volume is loud and clear compared to my W910i (which I'm using as a second phone).

Agreed with aruja. I'm very satisfied with my N96.

I'm sorry to hear of your predicament.

I would advise you to bring the phone back to the shop you purchased it from and ask them to test the set or arrange an exchange if possible.