Remove voicemail icon

I have a Samsung galaxy, but I think this should work for your ace:

Go to Settings
Applications
Manage Applications
under All go to Dialer
Clear Data

This won't clear all your contacts, favorites, and calls log. At least, it didn't for me. So it should just erase any pending notifications you have on screen relating to calls.

Try Dialer Services, too; I did both just in case.