playing dvd

[norman]

I use Ubuntu 8.04.1 and would like to be able to play ordinary DVDs.
When I load a disc, Totem opens, the DVD starts to play and then an
error message, suggesting that libdvdcss is not installed, appears
however, it is. On my recently purchased Dell Inspiron 1525 there is a
piece of software called LinDVD, which does play an ordinary DVD. I have
checked, using Synaptic, but it does not appear on my desktop computer.

I would be most grateful for any suggestions you can help me with.

Norman