First go into your Flash Publish Settings and select the option to Permit Debugging. That can help by adding more information to the error message string(s). See if the error message provides a trail to track down where the problem arises in the code. The order of tracking goes from closest to furthest, so the last line identified might help you find where it all begins at least... the first line identified is where the error actually erupts.
If it is a component issue, you might be able to solve it by gradually adding different components into the library one at a time. If there error goes away, the last component added is likely the missing link.