We sailed through the Millennium.... but what about 29th February??

We have 3 servers (Sun and NT) running V3.1.2.20.
These all allow the command: q event * * begind=02/29/2000
We have one server (Sun) running V3.1.1.1. This returns an error with the
above command.

Is this expected? Is there a quick fix?
Does IP21577 fix it, or should we be looking at new versions?
Can we move direct from v3.1.1.1 to v3.1.2.50?
Can we move direct from V3.1.1.1 to v3.7?


Thanks for any information,
        Chris