Wallpaper reset and program close bug. please help

[#1]

Hello,

I just got an Xperia Play and its great, but I'm having a few problems.  First, whenever I set the wallpaper, it sticks for a few hours, then eventually just switches back to the default purple wave image.  Is this a setting or a problem with my phone?

Also, I've been experiencing some issues when playing certain games (especially Asphalt 6).  Some screen will not render correctly and just be splotches of random colors.  Also, the game will just random close after it starts to slow down a bit.

I would appreciate any advice on if this is normal or easily fixable.  If its a real issue with my phone, I have 13 days to return it.

Thanks for any advice

[Uliwooly]

are you using any taskiller?

[#3]

No.  If it makes any difference, its the live wallpapers that are changing back to the standard wallpaper.

[Uliwooly]

ok if you got a live wallpaper from the market, uninstall it then reinstall it and see if that solves the issue