I also have a similar problem, I have had my car 206 roland garros (v) for a couple of months, and it was fine for a few days, then the speedo dropped to zero when I was on the motorway, so I quickly switched the ignition off and back on whilst driving and it worked fine for over a week, then all of a sudden on the motorway the needle went from 60 to 90, so I did the ignition again, again it worked fine for ages, but for a couple of days now it wont work at all, I think maybe it is something to do with the computer as all the connections look good, so tommorrow I will try disconecting the battery for a minute, which on older cars was like ctrl-alt-del on a pc, and fires everything back up again, not only that my car had an auto electrician out to fix my stereo before I bought it, and I think maybe things needed to be reset properly and he didnt do it, failing that I may have to pay a peugeot dealer to plug it in to their computer and reset it, even if it doesnt work they will at least be able to trace the fault.
Any other suggestions???
I will let you know how I got on
dave, August 2008