Barjon's chart looks pretty close to mine - I couldn't post it as I can't seem to disable all of my popup killers/firewall crap to be able to post an attachment on here :-(
Yahoo data is spiky, reminds me of MyTrack UK data 🙂 But I don't think it's just a problem of unfiltered trades though - often the volume is just complete crap, out by billions, and you get sometimes get pure errors like Close > High. The only reason I've spotted all this is that I've been using Yahoo to get free UK EOD quotes into my (excellent BTW) AmiBroker package and noticed discrepancies with the Reuters charts I happened to look at during the day. Do a bar-by-bar comparison and sometimes you think you're looking at a different stock they are so different. I'm in the process of moving over to MSN MoneyCentral, which AmiBroker also supports as a free EOD feed, and so far it looks a lot better. It also has the advantage that you can download 5 years of historical data in one operation, instead of splitting it up into 200 day chunks like you have to do for Yahoo.
KenN