Hi Craig,
I have no experience of Rovers but sounds like the master cylinder not releasing the pressue in the lines when you release the brake pedal. Is there anything stopping the master brake cylinder returning completey? Also, read this tutorial...
http://books.google.com/books?id=5rW...age&q=&f=false
Is your master cylinder from a car with rear drums as these have a residaul pressure valve, but you've probably checked that already.
good luck,
...peter