I have an Epson SC740 that was not being detected by Mac OS X (retail). I found a work-around that that seems to work. In the terminal I su'ed to root. I then copied the SC740.plugin file from the Printers folder to the /System/Library/Extensions folder. Rebooted and opened up PrintCenter. I was able to select the printer, and print succesfully to my Epson SC740. I hope this helps anyone else who is having problems with printing.