[1.1.2] SMS.app "message waiting off"

I searched on these forums as well as on others and can not find an answer to this...

Does anyone know why every time I check my voicemail, right after I hang up, I get a text message "message waiting off" from some general number out of canada - I am in the US. I also get a "you have 1 new msg" text from the same number when every someone leaves me a vm. The odd thing is, I do not get these texts when I put my sim card back in the razr and check vm so I assume it is a setting or plist edit I need to do on the iphone?! I'm on 1.1.2 and a small gsm in the midwest. Since this does not happen on the razr it must be an iphone issue right? Any help would be appreciated!

Edit - The area code the messages are coming from is 600. (Area code 600 is a non-geographic Canadian area code, reserved for specialized telecommunications uses such as teletype, cellular, ISDN and mobile satellite communication services.)

Thanks

anyone on this?!