V600 Newbie - Software question

Hi group.

I've just got the V600 on a new contract and was wondering what the
latest software version is?
The one problem I have found is that sometimes a few calls made/received
have no sound on my end (i'm not sure if the other end can hear me, but
will check up on that too).
Has anyone else had the same problem?

Thanks so much for the help


Dylan F.