bro, thanks for the reply.
for the 1st problem, the games i downloaded are definitely all from android market. not to say all games also gg, the most noted ones are NinJump - chance of happening about 50%
Fruit Slice - about 30% chance of happening
Alien invasion - happened once or twice
iRunner - finished the game, so far only happened once

my fren suggested me to uninstall and then download and install again..but i doubt that will work
any ideas...?

the 2nd problem, dun think its the 3g signal is weak at the particular time, because once i off and on back the phone, straight away can online with data network
i nvr knew there's ppl reporting this problem already...that means so far no solution for this yet ?