Screenshots in MAME all Black?

[MaxAsh]

Running MA 2.10 on Windows 7 32-bit.  Whenever I'm using MAME and attempt to use the Print Screen function to create a snap for the game, the image comes up as simply all black. I checked all the path info (tried both long and short as well). When I looked in the snaps folder, images are saving there, but they're all just black. No issues with other emulators, they save screenshots properly.

I only found one other forum topic (several years old) related to this, and there was no resolution posted. The only advice I saw was to use FRAPs instead. Has anyone else encountered this and found a fix? I have installed MA 2.10 on two other MAME setups, both with Windows XP, no issues with screenshots. Wondering if it's Windows 7? Very strange.

[Generic Eric]

I don't know about print screen, but have you tried the F12 button?

I'm going to add an F12 button to my cab.  Not sure if I should conceal it on the back of the marquee box, or just put it on the CP.  Most games I play are from the current high score challenge.