First, I'd like to point out that in our next release (v1.5), since we have a Column Chooser feature which allows you to add/remove any number of Work Item Type columns/fields from a query results view, this situation will never happen.
In the meantime, there are a couple of ways to fix this sitution in v1. The simple way is to unassociate the project which contains this query in the TeamLook Options dialog and then reassociate the project. This will refresh the views and bring back the columns you lost.
The harder way (yes, that's actually 11 steps using the Outlook Customize Views dialog!):
1. Right click the header and choose 'Customize View: Messages'
2. Click 'Show Fields'
3. From the dropdown 'Select Available fields from:', choose 'Forms...'
4. On the new dialog 'Select Enterprise forms for this folder', select TeamLook from the Personal Forms section.
5. Click 'Add ->'.
6. Close this dialog.
7. Back in the 'Show Fields' dialog you can now see your available fields (TLXXXXXXXX).
8. Add the field you need.
9. Close this dialog.
10. Now choose the 'Format Columns' option from the 'Customize View: Messages' box.
11. A new window will appear that will let you retitle the column since it will by default want ot call the column TLXXXXX.
Cheers,
Juan