is it true that celcom 3g network not stable??

coz im using sony erricsson phone...set the network GSM and 3G..

but it hard to make call or received a call...

i go to celcom center and they told me to change to GSM network only..

and they tell me that 3G network not stable..

after change to GSM network the prob already solve..no prob..

so if 3G network not stable how can i make video call??

anyone face the prob too??especially with sony ericsson phone one..

im MNP user..

my celcom line still suck till now...

line not clear at night..voice not clear...sometime when talking in the phone cannot hear voice..

if noon no prob...

if u guys encounter same prob??

with sup line also terrible at night..why celcom like this??

same area...noon and night...

my place is alor star...

wondering why it happend...

is there possibility that my phone the one is problem??