Hi
I'm in the UK and had the 232201 version of 3.3.5.2 before, and though there is a 232201 of 3.3.7 available, I decided to be reckless and first try Vigor2820V3.3.7A_STD211011. The update went well, and if anything, the broadband connection speed (down) shows as higher than before. Running the GRC DNS benchmark tool used to show the Draytek's internal DNS cache server as sometimes being 'unreliable' and the new FW seems to have fixed that too.
As to the Cisco phone, I made one call and it dropped the call after 15 seconds. The caller called me back and it lasted a whole 1 minute then the call dropped again. It looks like it's behaving much the same as before, but I have another trick up my sleeve that I've not tried yet; a spare (new) Cisco 1252 WAP in stock. I'll fire that up tomorrow just in case there's a fault in my current one (something I should have tried before, but never thought to do) and thus see if that helps; unlikely, but you never know!
I'll report back with my findings (it could still be this Cisco WIP310 that's duff).
Bri
Update: I used to get 20% of the DNS servers reporting as 'unreliable' and the new FW has totally fixed that. Forgetting the VoIP issues for a moment, this seems to be a very significant improvement over 3.3.5.2 in that area!