I can't help you about the 3 network,but i bought a HTC Wildfire 1 month ago in the UK[ PC World] to bring to Turkey.
I downloaded the latest version 18.104.22.168 & it was totally useless.On trying the 'Skype test call',i heard nothing,it wasn't even 'choppy',i heard virtually nothing!!!
After many nights trawling thro' Google with many download sites taking you back to the Skype latest download i eventually found a site listing many old version downloads.Someone on the skype garage site said that he went back to v 22.214.171.1243 but that didn't work for me,v126.96.36.1994 did tho'.Just remember to turn your earpiece volume down to 50% to stop the choppy sound & reduce feedback.
Go to the bottom of the page for the downloads.
android old apps skype
This site won't let me add a link,so ''read between the lines'' & hunt it out...lol...
Hope this helps, Martin.
The choppy sound is related to the HTC Proximity sensor. If you either keep the phone horizontal, or use the headset, it works fine.
The problem has been there for a long time and Skype need to sort out the app to resolve this issue (not seen on other VOIP apps).
It's strange that on some Wildfires turning the phone around & using the loudspeaker[eliminating the proximity sesor] solves the choppy sound,but not on all...like mine!!!!