hi guys, newbie in this thread

just wanna ask all the experience user of 5800. I got mine around 3-4 months ago. 1st month was ok but 2 months recently , i dunno what have caused it, my 5800 oftenly off by it's own. After self checking, i dunno maybe the battery longgar or what, I put some lil piece of paper to make the battery compartment tight. This kind of problem always happen when the 5800 in my pant pocket. U all know rite, sometimes when we sit, the phone get a lil bit pressure. But mine automatically puff-off.Also happen when I hold it firmly.

No problem with the software or application. Anybody can help me.Btw, mine is Ap set.