edit: you are correct.
You're a C-Class Corp right? Therefore you pay the corporate franchise tax. If you go to the link on the page entitled "Franchise Taxes Here": http://corp.delaware.gov/frtaxcalc.shtml
it tells you what it should be. Your fee will vary depending upon how many shares you have outstanding, but I'm guessing you have less than 3,000 therefore it will be $35.