I work in IT and I have 2 users having similar problems.

When trying to copy events over from 1 calendar to another, it works for the
first, and sometimes, second time, then after that they receive a pop up
error stating "Cannot copy items. Changes made to the item were lost due to
a reconnect with the server."

Restarting Outlook resolves this in about 2 out of 5 times. The only two
ways the users can get around this is to:

1. Copy the event to their desktop, then onto the destination calendar.
2. Double click the event to forward, then once a new email is created with
the event as an attachment, the attachment can then be dragged to the
destination calendar.

There seems to be no common denominator that I can find. The users and a
couple of the calendars they manage (they're administrative assistants) are
located on different servers, which would raise a flag that perhaps it's
moving from 1 Exchange Server to another that's causing the issue, except
that for a 1-month test period, one of the users and all of her calendars
were recreated on 1 single server. Still, same error.

Any ideas? This small problem is causing our work to fall behind as we're
wasting too much time researching this and coming up with nothing. These are
Gov't employees who work for high ranking military personnel, a simple
"You've reached the limitations of the software" answer just isn't good
enough for these people, so this is something that MUST be remedied on our
behalf.

Please help!!!

I'm sorry, I forgot to mention this is Outlook 2007.