I haven't tried Video Calling, I don't really have a desire to use that feature anyway it's just normal phone calls that won't work...
I've got the latest firmware installed :
PDA:KG1 / PHONE:KF3 / CSC:KG1 (OPS)
The 3G signal is a bit dodgy, sometimes it's good, sometimes it's not.
My service provider does support video calling but again, that's not the problem I have. I can't even call the Recharge service and check my credit balance!