It's poor taste to use words like "urgent" in topic headings. An emergency on your part does not constitute urgency on anyone else's part, and many of us simply ignore any topics with words like "urgent" or "help" in them.
ANYWAY: if it is truly urgent, try removing and reinstalling webmin as it is generally quite good at detecting where the various components are installed. Also, make sure you're running the latest version of webmin at
http://www.webmin.com/ as the install script for it is continually updated to improve the component detection process.