got one time my w850i suddenly got no line. i mean, i think the phone has trouble detecting network. it's not a sim card problem cos i used my fren's sim card that's ok on her phone, but on my phone same thing happen. and it's definitely not cos of "longgar" cos i dont tukar-tukar simcard. only use mine. after almost half a day, it became ok. it has been ok ever since. but really scared if the problem comes again. do u think i should go to the dealer and check? or is it cos the phone juz meragam for a while?