The best thing really would be for you to zip up a bare bones example of the problem we can look at, but as a minimum you need to supply more information if you want some help with this - eg:
- What version of the compressor are you trying to use?
- How are you trying to use it - as a post build step? in a separate msbuild or nant task?
- what does your project file look like? are you pointing to the right locations?
- have you got the right assemblies?