*moves*
On-topic: I had the same problem when I first played AO. It's one of the most devious things OWI has done in a game. But if you haven't saved 28 muds, then you haven't found all the secret areas. Try
Sinjin's walkthrough to find what you've missed. The great thing about Zulag 1 is that you can backtrack through the entire level so you don't have to repeat yourself too much.