I have the same phone. The G displays after I have sent a picture message or connected to the t'internet. It goes away when you turn off the phone. Never seen the E symbol.
Try...
http://uk.samsungmobile.com/wcms/pro....jsp?swType=UM
OT: How do you find the signal strength? Mine's pretty poor. Also, do you find that you are prone to brushing the touch sensitive keys and dialling someone by mistake? Did this the other night and woke me mate up. He wasn't best pleased!!