I have the same problem. The only thing I have found until now is a manual for a D90 and this helped me on the way.
Meanwhile, I am still looking.
I even asked the manual in the shop where I bought him (second hand), but they could only give a Japanese version...
I did a quick google search (bored on Christmas Eve!) and ended up at some Yahoo Fostex users groups. The search engine at that site listed a post indicating that no PDF manual is available for the D80, but you can buy one for $26. I think the same applies to the D90. I hope this helps.