andra,
thanks. let me summarize what i understand so far (please correct me if i'm wrong).
1. after you enable offline vault, disabling it does not delete the files. the files will need to be deleted manually.
2. if you delete offline vault files, but do not delete the registry key that refers to the offline vault folder, EV will not re-download the files, because the registry shows it as "already downloaded".
3. minimum offline vault size is 100MB. setting the value lower than this will only result in the value being "reset" to 100MB after outlook is restarted.
4. increasing offline vault size results in more items being downloaded from vault.
5. however, decreasing offline vault size does not result in items being deleted from offline vault in order to comply with the new limit. we will then need to delete the physical offline vault files and remove the registry key that refers to that folder. offline vault will then re-download the items according to the new limit.
thank you!