If you own the Retro USB AVS, make sure you update to the latest official firmware version which is 1.20.
The last few firmware releases were beta versions and had a few reported issues, but this seems to be the final firmware update on the AVS from Retro USB.
What does it add? One addition is the variety of color palettes you can now use which included the original, unsaturated and even a popular NES emulator color palette. Head over to retrousb.com to get the update and check out the differences in colors from my Bionic Commando screenshot captures.