Noticed this too. No wonder my iPhone 4 and other is OK. Looks like it's the antenna problem in iPhone 5 .
Not on celcom network I guess. I think apple should implement the 3g only option.

No wonder people jump ship !!!

3g is always full using the same Sim on the other phone. But always or most of the time on edge when put in iPhone 5.

So... Is the Celcom problem or the iphone5?

My 3G can stuck for awhile only.. Always back to edge. But using the same phone in Taiwan and Singapore there is no such problem.

Should report to Celcom? Cos no point report to apple... They are useless junk working there.