[HELP] Post anchors

[JackThomson120]

I'm having a few problems with the post anchors.

If I use a URL like this:
showthread.php?p=182822#post182822

It goes to post 182822, but then scrolls back to the first post.

However, when I use this URL:
showthread.php?t=38459#post182822

It works perfectly fine. Whats the difference between the use of $_GET['t'] and $_GET['p']? Does $_GET['p'] callback a javascript function?

Thanks for any help!