Trouble printint to a Dell Laser MFP 1815dn.
Check if the Dell driver is PPC. If it is, and if you installed the first version of Apple's latest Security Update, then that's probably where the issue is, because it broke Rosetta, the software which runs PPC code under SL. Re-install the Sec Update (the problem is fixed in v1.1, which replaced the goofy version on Apple's servers) through Software Update or by downloading it again, then re-install the Dell driver, and try again.
Apple stuff is great, except for their casual disregard of their customers who want to use any product that is not Apple
I'm sorry, but that's non-sense. I'm no fan of Apple, but they're no better and no worse than any large corporation of this type. Mostly, they do things which make business sense as they see it -- which is exactly what you'd want, if you had serious money invested in Apple shares -- wouldn't you?
In this instance, it was up to Dell to release an Intel Mac driver for this printer/scanner, which is, what, 5 or 6 years old? If they didn't, it was probably because they decided it didn't make business sense for them to spend money on developing and testing one. Keep in mind that Dell and Apple and Microsoft and all the rest are in business to make money, not to support every single customer for ever and ever and a day.