While it has very little to do with MyPublisher, I do all of my pages on PE2 on 12x12 canvases in 180 dpi. I have them printed at Costco (only $3 for a 12x18 print) and they have all come out crystal clear. Most elements that we use are vector based so they resize without any loss of quality.

If you are resizing your images down for MyPublisher purposes there should be no problem.

As for MyPublisher, their customer service stinks and refuse to use them after a bad experience and some terrible printing.

__________________
"If little else, the brain is an educational toy...The problem with posessing such an engaging toy is that other people want to play with it, too. Sometimes they would rather play with yours than theirs." -Tom Robbins, Even Cowgirls Get the Blues