If at any point while using GeneDesign an error occurs, please do the neighborly thing and report it! There's an error reporting form here. It will ask you for information about your computer, your browser, and the sequence data you plugged into GeneDesign (Don't worry, it will tell you where to find these things). If you take the time to fill out the form properly I may have a chance to fix the bugs.
Errors include processing or loading times that don't resolve, incorrect or inaccurate output, rendering errors (things aren't in the right places or are missing altogether), and any error messages that say "Programmer Error".
Even if you don't have an error you may wish to make a suggestion.