Of course that's what he's saying. Those voice mail systems are pretty
simple really--having worked with several Octel VM systems for years I
can't think of any method that the actual voice mail could have been
delayed from being put in the box. Short of a major drive crash of
course. You can check the box one SECOND after the caller hangs up and
the message will be there.  On the other hand there have been lots of
reports here about the VM *Indicator* signal not being sent until later
(or not at all) or getting left on.  

I would bet you $10 that's the case.  Where would the message be for
four days if not on the VM server?

That MWI delay is one of the reasons I got rid of Nextel.  If you are
out of range for long enough, it may take a day to get your messages
when you get a signal again.

Yup.  When a caller is prompted to leave a message, that announcement is
coming from the VM system itself, and when a message is deposited for
the recipient, it's deposited directly into the VM system.
Subsequently, the VM system is supposed to send a signal to the
recipients handset to inform them a new message is available.
Regardless of whether the "new message" (MWI) signal was received by the
reciopient, the message can still be retrieved at any time after it was
deposited.

Virtually all carrier class (NEBS 3 compliant) VM systems (Cingular uses
Octel and Anypath by Lucent) have multiple disk drives for a message
store.  Single drive failure has no impact on subscriber service -
that's what makes them carrier class - carrier class communication
systems are fully duplicated internally, are externally connected with
multiple fault-tolerant interfaces, and are designed and operated to
tolerate single component failure without adverse impact to subscribers.
 And no, you probably don't want to see the price tag.

http://www.lucent.com/solutions/anypath.html?3