broadband dial-up (speedtouch) intermittent problems after installing Norton Internet Security 2010

This is the situation at work:

 

Dell XP PC (SP3) connected via speedtouch modem (via usb) thats connected to telephone line for broadband connection.

Its also connected to a hub that shares (access to the net) for a laptop (& one other PC)

 

The Dell PC and the laptop both were working and had access to the internet and outlook was also working perfectly. I installed Norton Internet Security 2010.

 

Initially the access to the net was ok. This is achived by speedtouch automatically dialling up & useranme & password checked and if all that goes okay - then bingo we have internet & thus emails on both the PC's.

 

For couple of times the dial-up fails with NIS2010 - so I disabled the firewall - and it got it going.

 

After about two weeks,  today - I do not have internet via dial-up working as username & password are rejected.

I have rechecked the firewall setting, also turned it off, re-booted many times - but alas no internet.

 

One thing I have not tried is to remove Norton Internet Security 2010 - but looking at the forums its may be an issue?

 

Any help?

 

Currently I only have access to the net at home yto post and review/check the above issues.