I've just got a TEC 2G and it comes with a later version of SmartTrak (1.0.4.0). If you PM me an email address I'll send you that version tonight when I get home (it's about 3Mb).
XP SP2 should ensure that you have the latest Jet updates (later than what you get in the Jet 4.0 update 8 download), which is probably why you get a message saying that you have newer files.
It does sound like some of your Jet files are broken. This page here details the file versions you should have:
Information about Jet 4.0 Service Pack 8
To check the versions you need to search for the files (usually in c:\windows\system32), right-click the file, select Properties and look at the Version tab.