DAC10,
re-stating your troubles again:
After reading this thread it seems that you had extensions that matched the mailbox and the did drop (9xxx) until a power failure, at that time you were re-numbered to the 2xxx range for phones and mailboxes. if during the re-initialize of the voicemail the tech acceptetd the default value for group lists (9xx) then you would loose the ability to start any mailbox with a 9. in the same vein 9 is defaulted on the MICS to be the access code for system programming->access codes->external code and much of the time the external code is removed and 9 is used as either the pool access or within the routing tables.
with the above in mind if you want to have the DID,Mailbox, and DN to all be the same it will involve a fairly complex process, almost the equivallent of reprogramming from scratch.
find out where 9 is already in use on the phone system and migrate those access codes to another number such as 8. you could then start changing the DN' to 9xxx (remember to go looking for the locations where the DN is used)
You would also have to re-initialize the flash again (losing all of the present config and mailboxes) and then make group lists some other leading digit such as 8 (it can be any digit from 0 to 9 and cannot be the same as any mailbox (remember the system coordinator mailbox and general delivery both start with 1) if you select 1 as the starting digit for group lists the special mailboxes would start with a 2 ie 2002 vice 1002)then build the mailboxes, aa tables etc (make sure you have some record of the way everything is set up now before you start.)
All of this is fairly daunting to look forward to doing I know, I would guess weather or not you would do it would be the ammount of frustration you are looking at with the dialing plan the way it is. JerryReeve
Communications Systems Int'l
com-sys.com