Programmer's assertion error

[Malia Zaheer]

I get this error when I try to use XPathAPI.getNodeIterator method:

java.lang.RuntimeException: Programmer's assertion in getNextStepPos:
unknown stepType: -1

The code snippet is:

          NodeIterator ni = XPathAPI.selectNodeIterator(root,
"//xsl:[EMAIL PROTECTED] =='"+ xp +"']");     

root contains the root element of xsl stylesheet.  I know the error is cause
by this line of code through testing.  I would appreciate any help in
figuring out why I am getting this error.

Thanks,
Malia