Blank screenshots on Android tablet I use ddms to take screenshots of my phone and it works fine, but when I try to do the same with my tablet I just get a black image. The phone is a Samsung Intercept running Android 2.2; the tablet is a ViewSonic gTablet with Cyanogenmod 7. I found a forum post that mentions that Tegra devices (like the gTablet) don't use fb0, so normal screenshots don't work, but it also claims that screenshots taken through adb connections work and they don't for me -- I get the same black image. Is that the reason ddms doesn't work on my tablet? Is there a workaround that will let me take screenshots?
I believe I have one of these device (mine is branded as something else but the US brand is the ViewSonic gTablet). I cannot recall if I have tried to do a screenshot with DDMS or not. I don't know why the forums you read would say adb would work becuase ADB uses the same method as DDMS. 

I will try my device when I get home from work today, in the mean time, I have read that these apps should work with the device.

All of these are paid apps, they may have a free/lite version but I dont know if they will work for your issue.
Screenshot ER - Requires Root
Screen Shot It - Requires Root
No Root Screen Shot It - NO ROOT REQUIRED (but I am not sure if this works)