The Rs. 50 all-day Mumbai Suburban railway ticket

Out of curiosity, one weekend I bought the all-day Mumbai Suburban railway ticket. This costs Rs. 50 and is only valid within suburban Mumbai limits. The ticket is valid for the entire day until mid-night, and is valid on the Western, Central and Harbour lines. There is some confusion regarding the limits, but I guess these would be:

• Churchgate to Virar, on the Western line
• Mumbai CST to Karjat / Kasar, on the Central line
• Mumbai CST to Panvel, on the Harbour line

By "confusion", I mean to ask whether the ticket is valid on the Khopoli line (beyond Karjat), and if it is valid upto Dahanu Road  from Virar.

Update (2010-December-23): Today's  Times of India newspaper carried an advert specifying that Virar to Dahanu is covered as well. Take a look at the advert below. It also specifies that there are 3-day and 5-day tickets as well, and that these are for the 1st as well as 2nd class.

Click to view larger image

Update (2010-December-05): Here's a scan of the ticket. In railway parlance, it is also called as the "Tourist Ticket" (or more correctly the "Second Adult Tourist -1day Ticket").

Click to view a larger image