Hi, not sure if this will help, but I recently set up a friends new Vista PC, worked fine to begin with but then started losing her broadband connection, sometimes it would work, sometimes it wouldn't. Not being familiar with Vista, 'twas my first time using it, did as I would have done with XP, i.e. checked all the usual connection parameters in IE Tools etc. All appeared to be ok, but the dropped connections continued. I then had a look in Vista's Control Panel, Administration/Services (can't remember exact wording's in Vista) and in Services found that Connection was set on Manual, changed this to Automatic and this appears to have cured the problem.
I do not like Vista - cannot understand why names of items we are all familiar with had to be changed - Outlook Express = Windows Mail, Add and Remove in Control Panel = Programs and Features ... why, why, why! There may be other name changes, but I don't know.