I'm in the same boat... did a couple of batches a few years ago, and recently picked up a can of pre-hopped malt to get back into it. I guess I forgot everything I learned back then, so I did the corn sugar thing too (just followed the directions in the kit).
Check out this section of How to Brew by John Palmer - it explains common off-flavors, and you might find that what you've got fits into one of the categories (the batch I just bottled had the apple-y/cider-y acetaldehyde taste to it, presumably due to all the corn sugar):
Reading through all of How to Brew on that site isn't a bad idea... I'm gonna go over it again before I try another batch. I should buy a copy of the book eventually.