[AlpGlide]

Originally Posted by CoolDragon

Looks like you are using dr800sg, in this case, download this: http://updates.irexnet.com/embedded/...-build1000.zip to restore to the v1 firmware.

I tried to restore to the V1 firmware, but something was missing, for example, there is no "airplane mode" inside "Settings", so wireless is always on, no way to turn off. I seldom use 3G.
some other missing stuff I can not remember now.
so I upgraded again, just disabled all advance option, zoom, pdf scribble and so on. "go to page" really helps.