I almost gave up trying to run grails applications on Glassfish v3. Today I stumbled on a solution that was so easy that I should be ashamed I did not investigate a bit further. The problem is with some OSGi headers and is documented here.
Others have had the problem and the solution I found on nabble was pretty simple:
Add the following line in BuildConfig.groovy in your project that should run on a Glassfish v3.
This helps with the problem not being able to deploy a grails app on Glassfish v3 when you experience the following hints in the log on GF:
SEVERE: Module type not recognized
SEVERE: There is no installed container capable of handling this application com.sun.enterprise.deploy.shared.FileArchive@68237947