Problem with playing a certain video dvd

[Paul Smith]

Dear All

I am trying to play a video dvd but I get the following errors:

with kaffeine,

"The source can't be read.
Maybe you don't have enough rights for this, or source doesn't contain
data (e.g: not disc in drive). (Error reading NAV packet.)";

and with totem,

"The source seems encrypted, and can't be read. Are you trying to play an
encrypted DVD without libdvdcss?".

However, I have libdvdcss installed. Any ideas?

Paul