When working with absolute path the dmxValidatorAjax.asp creates a relative path instead. This results in the form just not submitting when relative path is not allowed. When you change the relative path to virtual then the problem is solved, but when you then try to edit the validator it ends up in an error and you can not edit the validation rules anymore.

I have the same problem when switching to shared hosting, I had to redo all my form validation with spry