It seems that the pingback/trackback code is php implementation or server configuration dependant. I don’t see any other explanation for the variety ot situations where trackback in/out and pingback in/out work or don’t work for different people.
For example, brianbonner, in opposite to you – my outgoing trackback works just fine, but my incoming does not work at all. Same with pingback: outgoing seems to work, but incoming fails 100% of the time.
As I mentioned in another thread, I’ve moved to Haloscan for my incoming trackbacks which works flawlessly and I guess I’ll just have to live without pingback until it is fixed and works for everyone.
fredrik: Glad I could help. Many people (incorrectly) use the terms pingback and trackback interchangeably. While the end result on the pinged blog is generally the same, the process by which the ping ends up on that blog is different.
If I was going to meander for a bit, I would say that I think the future is pingback and it will eventually deprecate trackback. Pingback, in my opinion, is superior because it does not rely on a blog author to remember to tell their blogware to send a trackback when posting an entry. It’s all automatic.
Having said that, trackback isn’t even fully implemented in all blogware yet so I can’t imagine how long, if ever, pingback will become standard functionality.