I also received a call from Wade and I promised I would post back here once I have had some time to test again.
Skype seems to be connected constantly now (although one message sent yesterday only reached me today) - so I think that has had a step in the right direction.
My second issue has not been resolved yet though. At roundabout the same time the Skype issues started happening I've noticed that secure connections out (SSH on a non-standard port etc) does not work except after several retries. Is this an MWeb problem? I don't know but I checked from two different lines here with two different routers (one with an IPCOP firewall sitting between lan and router, the other directly connected to adsl modem) and both are giving me the same result. SSH initially connects then I get this from the server auth.log:
sshd[10887]: fatal: Read from socket failed: Connection reset by peer [preauth]
Any ideas?