I was able to install the mobile partner version which had the voice call UI on my computer. But then, when i tried to call using it, it said that calling not supported using current device. i am using version 11.005....sumthing sumthing.
so i guess we need two set of things.
1. install mobile partner with voice call ui.
2. have a mobem firmware which supports voice call.
though maybe, if you upgrade the firmware of e122, then the higher version of mobile partner is automatically installed