Hi,
Probably the best plan would be to uninstall the version of Vodafone Mobile Broadband or Vodafone Mobile Connect that you have installed using add/remove programs or programs and features (depending on which verison of windows you are using).
Once you've uninstaled it, run the clean up tool that can be downloaded form here
When you run the tool make sure you tick "settings" and "data" when given the option.
Reboot your system, then try instaling the version of Vodafone Mobile Broadband off the K3770 again.
At this point all the things about having the device set as default still applies.
I think it's probably the case that the lite version you previously had (which is specific to the K3570-Z doesn't include drivers for the K3770, so you've got a kind of mismatch there between devices and appropriate Vodafone softwware. The steps above should sort it out, but sometimes RAS 631 will be caused by another applciation trying to poll the port associated with the K3770.
A clean boot (instructions are contained in the thread here) will rule out background applications as this stops them running onstartup. On the same thread there are some dial up networking instructions that might also be worth giving a try as this will identify if it's a problem with Windows addressing the K3770 or the Vodafone software addressing the K3770.
Let us know how you get on and what happens if you still run into problems after trying the above.
Good luck!
