Under the policy set encompassing the information stores for exchange, the
'Versions' kept should be set as follows:

Versions Data Exists 1
Versions Data Deleted 0

Then have the following in your command batch file:

%exc_dir%\EXCDSMC /adsmautodelete:* /ifolder:x     (substitute 'x' for
required days retention)

This automatically deletes the active versions of the information stores
after x days.  As you are not keeping any inactive versions, the expiration
works correctly.

Stu