Speckles in my yellow

I have bad print quality on my sc-500 using colorchoiceII. My files are set in rgb sent as rgb eps and printed as rgb and my color quality is nasty. I have speckles in the yellow that are little green spots. I have seen this problem before but on an sp300v and cannot remember what solved it. My head height is set to standard which is as close as the machine allows. Ecosol Max inks with the appropriate profiles. Does anyone have any suggestions?

 

I'm working in Corel. I think I tried setting in cmyk but will try again and send as cmyk as well. One thing that definitely points to profile is that when I turn off profiles by unchecking "color correction" my colors print great. This limits me because out of corel the only colors that will print are ones that already show the cmyk percentages in the pallette. If I try to pick from the Pantone swatches that just show the name of the color and not its attributes it prints black. I also now remember what fixed this problem when my boss had an sp300v. I quit using Roland's software and printed directly from Flexi. I don't presently have Flexi but printing straight from Corel seems to be working on my solid colors. Tommorrow's test will be photos which I am guessing are not going to turn out due to their need for processing. We'll see. Thanks for your input, it has definitely been spot on.

 

Sadness,
I tried everything suggested and went through all the steps from the rep and headquarters. My solid colors print perfect when I do not allow colorchoice to do color correction. When using color correction and profiles it not only throws speckles in the yellow but actually shifts the cmyk images away from each other. Red sticks out the bottom and blue out the top. Roland came to the same conclusion I did - it's their software. And their final reply was "We don't support ColorChoice anymore."

 

a picture of the problem

The problem is a little clearer with this picture, the cyan plate is obviously shifting to one side by about a 32nd of an inch only when color correction is turned on

 

One problem eliminated

Thanks to the posts here and the resources gathered (manual) I have solved a portion of my problem. I have now fixed the head alignment and have no shifting colors. I believe the reason this didn't show up in my "non color corrected" is that the density was much higher and the ink mixed better. However I continue to have rip issues and still have speckles in my yellow unless I do not allow Roland's software to do color correction. With the progress I have been able to make I can now print photos and stickers for at least the non-artists. It will only be those that stick their nose to the print that will be able to see the blue specks in my yellow. I am working on getting wasatch softrip as I also recently bought an FJ500 and the Roland Salesman said I could get the Colorip upgrade without the original cd (ownership of the machine was enough - I hope he is right). Again anyone with a legit copy of flexi or softrip for sale leave me a note.