Voicemail issue

[bigmatt0211]

So I had an old 2g iphone that worked great. Everything worked. Eventually the screen cracked on it, so a friend of mine had another 2g and gave it to me. So I upgraded it to 3.0 and jailbroke/unlocked it. Now, for whatever reason, people cannot leave voicemail. It continues to ring and eventually says the customer is unavailable. The previous 2g had the 2.x operating system. I am only worried about the regular voicemail. I know that without the dataplan, I cannot have the visual.

So my question is why is this happening? I called ATT and asked and they said that because I dont have the iphone data plan, it wouldnt work, but it had worked previously. Is it because the 3.0 OS? Any assistance would be great. Thank you.

[mr.whit]

tell AT&t to activate voice mail they will ask you what phone you have, tell them any phone that you have had. AT&T is looking to to charge you a special iPhone plan for voice mail. They will give a voice mail phone number, plug that number in and it works fine.