Strange proxy issue.

Hi All,
We have found the following issue and can't work out why this is happening.
We have a mailbox which other users proxy into. Each proxy user has full rights.
From the main account without proxying in, mail can be opened with out problems.
If a user proxies into the mailbox they can open mail without any issues.
If a proxy user searches the mailbox for a particular message and opens the email it opens as if its being replied to.
This only happens if the mail has been searched for via ctrl f or the search window.

Groupwise server is up to date and client is 14.2.2