Very likely, you have a UK Jaguar, which is PAL-I, sound frequency is a bit different.
Most of Europe uses PAL B/G. I had the same issue with UK Jaguar with a German TV.
http://www.ee.surrey.ac.uk/Contrib/WorldTV/broadcast.html
As was said, a Jaguar RGB cable will solve the problem, and I recommend that highly.
One can be made with some ribbon cable, (an old floppy disk drive cable for example),
and all you need is the edge connector. You can then solder a SCART socket on the
other end, then plug in a normal SCART cable between the socket and the TV as normal.
You can also buy adapters still I think online, an official SCART cable is not vital.
The RGB cable provides the clearest possible signal, and excellent stereo sound.
Thanks, it's good to hear that the jaguar is probably not faulty :-) Will try to get a cable or perhaps ask a friend to build one.