Google App Engine (app-engine run) script problems

After I run Google App Engine locally (after installing GAE SDK and Grails GAE Plugin) by:
grails app-engine run

it runs fine but when I Enter Ctrl+C to terminate this process, it does
not shutdown and leaves the port open and I cannot run the command again
because I get Address in Use Exception.

Has some one developed a solution for this? I would appreciate if the modified groovy
script can be posted.