The only thing I can think of (besides the jugs) is to check and make sure you are in the right place. There are two levels to Howard's, and you should be on the lower one. The walkthrough that I saw described this as a "cabinet" not a chest, so you might check further to make sure you are trying to open the right thing.
I wouldn't expect the jugs to cause a problem as long as you got the coordinates you needed from the walkthrough.....
"Once you give up integrity, the rest is easy." Anonymous