nasty beer????

It's possible that the beer didn't carbonate in 1 week at 66F. Table sugar will take a little bit longer than corn sugar (but does just as well). I'd warm them up to the high 60s again until the carbonation is right. In the future, I'd allow AT LEAST 2 weeks for carbonation (tho' it usually will be done sooner).

As the other poster said, prime in a bottling bucket, about 4 oz by weight for 5 gallons. Boil the sugar in a little water to dissolve first and stir it in gently. Never heard of sugar in the bottom before... are you sure it was sugar and not yeast. It is normal for homebrew to have yeast on the bottom of the bottles... Taste the sediment to see if it is sugar or yeast... When you pour, just leave a tad of beer in the bottle so that you disturb it as little as possible.

Derric