I had a problem today… at a customers laptop the Offline Files tab was missing…

The solution vas a registry setting:

Next, navigate to these Registry keys:
=====
HKEY_Local_MachineSoftwarePoliciesMicrosoftWin dowsNetCache

If the entry for “NoConfigCache” is set to 1 (that’s one), it disables the
tab from appearing. Changing it to 0 (zero) should make it appear. Make
sure to save your changes.

I found the solution here after some googling.

Source:

http://www.tabletquestions.com/windows-xp-tablet-pc-newsgroup/2852-synchronization-offline-files-tab-missing-2.html