Did you try one of your HR24-200s on the DLP to see if it also occurs on the HR24?
Also how old is the bulb on your DLP? Could it simply be that the bulb is going - you can sometimes see strange results with an old bulb. Its possible you didn't notice the orange issue until you looked for it when your receiver changed?
Personally, I had an HR24-500 and now have an HR44-700 and I do notice a picture quality difference, but mostly that there is better shadow detail on the HR44 than the HR24 (HR24 was crushing blacks) - I think that has to do with the HR24-500's RGB signal being incorrectly processed by my Pioneer Elite plasma (assuming 0-255 when the signal was 16-235). I don't notice any problems with skin tones being orange or anything else.