Is anyone having problems with sharing mailboxes via MountPoints in the 6.0 web-interface?

I upgraded from 5.0.18 to 6.0 yesterday and now I have to type the search in manually to view the contents of a mailbox.
It's not a permissions thing as I can view the mailbox if I type the search string in myself.
The MountPoints are set up as per Zmmailbox - Zimbra :: Wiki and have been working for ages in 5.0.x releases prior to upgrading.

If I try to access the mailbox by clicking on it in the left hand "folders" column then it doesn't add the MountPoint in front of the folder name (e.g. when trying to access /Admin/Inbox it goes to /Inbox instead with the search string in:"inbox")

After a bit of playing around, it seems that going to in:"/admin/inbox" redirects to in:"inbox" but using in:"admin/inbox" as a search works as expected.
The web interface must be prefixing the search path with a / and hence getting redirected to my inbox.