The T-Stick won't be made by Telecom, see if you can work out who actually produces the thing and see if there's any newer software for it. Sounds like a repeat of the horrible problems the original Vodem had with OS X.
You could try looking into putting a caching DNS server on the local machine and pointing the modem at that instead, a bit of a hassle but it may help.
There's an update for the TStick for Windows 7 but not for OSX 10.6 http://www.zte.co.nz/main/Product_Downloads/MF636_downloads.htm
From Telecom: The Firewall traffic that you see is normal as this is the Mac > communicating to Xtra DNS servers. This is required for translating > website address to IP address to find where a website is. ~~~~~ I personally would not call over 4000 messages an hour to Console from the Telecom Connection Manager normal either but that is still happening and was the same with Leopard. Telecom didn't reply to that part of the question.
The 1 KB per second upload is still happening and I'm 99% sure it was the same with Leopard.. Uploads are not being charged for till end of January so hope they have it fixed by then. ~~~~ What with the over 3 months of hassles trying to set up a Direct debit to pay Telecoms bill ~ Given up.. Usage meter 6 days late at the beginning of Nov which took three days to fix then it was 3 days late two days ago. Usage meter is also set for 3 Gb rather than the 4 Gb I changed to during the usage period before last.
I got the Tstick given away by XT to their broadband customers inc. 500MB/$29 prepay. It's advertised as OSX compatible; however, it's a sad joke; the Telecom Connection manager constantly writes messages to Console generating pages and pages of crap and there's a constant traffic of about 2KB/s from mDNSresponder to Telecom's dns servers (188.8.131.52 & 184.108.40.206) - blocking this traffic stops DNS resolving. However, it's completely unnecessary when you are not accessing a new page/service. This makes the Tstick unusable as a 500MB allowance will be burned up very quickly just through unnecessary DNS server access.