Passing a script path containing a minus character to groovy.bat seems to interpret this minus character as a commandline switch.
c:\> groovy c:\test\my-qtest\foo.groovy
Caught: java.io.FileNotFoundException: c:\test\mytest\foo.groovy
So, c:\test\my-qtest\foo.groovy gets turned into c:\test\mytest\foo.groovy.
I don't know if this is an issue in the .bat - script mess or a code problem.
What's for sure: this worked in 1.6.1!