[abhasbajpai]

for internet access point don't use anything for proxy, leave that field blank
what my settings are
Connection name :- IDEA_internet
data bearer :- packet data (it could be gprs also depends upon the phone)
access point name :- internet
network type :- IPv4
phone IP :- automatic
name server :- automatic
proxy server Address :- none (or leave it blank depends on the phone)
proxy port no :- 0 (or blank depends upon the phone)

when i started using these settings my problem resolved.