Todd,
I don't have any specific knowledge of the Sharp LCD PJ, but I noticed a similar effect on my Sanyo Z1. The only way to fix this was to go to a different picture preset mode. On my Z1, the default mode was named "dynamic" or "high contrast", or something like that. I switched it to the "Real" preset and the "S" shaped gamma curve went away. I would suggest trying any other available preset modes on your PJ.
If your Sharp PJ was designed as a presentation PJ then it's possible that you are stuck with the bad gamma curve.
Mike
I don't have any specific knowledge of the Sharp LCD PJ, but I noticed a similar effect on my Sanyo Z1. The only way to fix this was to go to a different picture preset mode. On my Z1, the default mode was named "dynamic" or "high contrast", or something like that. I switched it to the "Real" preset and the "S" shaped gamma curve went away. I would suggest trying any other available preset modes on your PJ.
If your Sharp PJ was designed as a presentation PJ then it's possible that you are stuck with the bad gamma curve.
Mike