Hi Chris,
What errors are you getting exactly? I know that when we first started testing our DCC process we ran into problems with OCR on some images because of how much "noise" they contained.
As a follow up question, what settings are you using? I've found that some Image Cleanup Options can actually cause more errors with certain images.
As an example, a large percentage of our images ran into errors particularly with the Decolumnize and Despeckle settings enabled so we don't use those at all.
We have a retry process setup to where if OCR fails twice, it retries a third time with all of the cleanup options disabled (decolumnize/auto-rotate unchecked and all additional options set to "no").
Grayscale is inherently more noisy than black and white, and in my experience they cause more problems with OCR than color because it is hard for the system to analyze the image with relatively little variation between the background and foreground.