Users changing 'open with:' not working/permanent

We have an issue with 'open with:' (within get info options) not permanently remembering any changes.

We have Lion Server set up as OD and when users login any PDF or EPS files are set to open using Preview, users then change this via 'get info' to 'open with:' (change all) Acrobat and iIlustrator. But, this only works for the present session. If they move to another mac or a mac is restarted, the options revert back to Preview, not a permanently change to Acrobat and illustrator.

Does anyone know how to fix this?