I had an 8830 that every once in awhile when someone would call the person calling would hear a loud almost fax machine sound. For me I could sort of hear them but it would cut out. So I thought it was something wrong with my 8830.
Well I just got the 9630 and it's doing the same thing!! It must be something setup with my phone number. The only thing that I can think of is I have IMAP setup to receive my emails.
ummm now that is a new one. have you contacted Sprint yet? I would ask them, if possible, if they could change your number and MSID. Sounds like someone in your area has a fax number the same as your cell number.