I recently purchased an unlocked Samsung GT-S5230 to use on AT&T network. The voicemail notification icon on the home screen does not go away after I deleted the voicemail. Instead, I receives a blank sms message from 0100 right after I deleted the voicemail. When I receives a sms messages notification, it always say I have vociemail. Here is what I did so far.

1. Contacted Samsung but they does not support this phone because I am not in their service area (Europe). They suggested to contact the carrier / soft reset / flash phone.

2. Contacted AT&T but they does not support this phone because it not an AT&T phone.

3. Soft reset (factory reset) - Didn't solve the vm problem.

4. Flashed the phone via Mulitloader with several firmwares (S5230XPKB1 => S5230XXIG4 => S5230ZCIK3 => S5230ZHIH3) - Didn't solve the vm problem.

I am running out of ideas. If you have solved this vm problem, please reply with solution. All suggestions are welcome. Thanks in advice.