I saw your note and I ended up spending quite a bit of time playing with it. I wasn't making too much progress so I ended up using the free online openid service at: RPX
I did get that working and I recommend it.
You may have reasons why you need to roll your own but if you don't I suggest that you try the service version. When I was trying to get php-openid working I did see some postings that were reporting how people were having problems with Yahoo and Google Apparently, they handle it a bit different than the rest. There were some suggested changes to get around it. There were also suggestions that it needs to be re-written for PHP 5. If you do a bit of searching on google, I'm sure that you'll find it.
thanks chris for your help.
i tried RPX before using php-openid but it was too slow and many of my site visitors are still using dial-up connection and RPX is not suitable for them, as well it need to start my own openid provider (we have mail our own mail service) and as i found php-openid wil give this option.