When I go to my profile it says I have 500+ posts. When I click on "see users posts" it comes up that I have no posts.

What the hell is that about???

Cant manage to search for posts older than late 2007 but I joined in 2004, How can I get to the rest of my posts?

When I click on your profile, all your posts come right up. As far as searching, click "search", then "advanced", clear both windows blank to just search for keywords/username with no date limit. If you click the drop down button on the "newer than" window where it says days, weeks, months and years you will see a blank space above days. Click on that, and clear the "1" out of the other window and the system will search as far back as needed to get 200 results.

As an alternative:

You click on a user's name in a thread, which brings up their profile. Click on the "show all users posts", and it will brings up a list of posts by that person.