Hello Mikesart
I believe you must uninstall Parallels as step 1.
Back in January, Parallels recommended that we uninstall parallels before upgrading to Leopard, then reinstall after the Leopard OS is up and running. (The web page where I read this has since been removed.) I believe it is still true. Build 5584 is the correct version, but you must uninstall your current Parallels (don't freak out, you will not lose your windows setup or applications in doing this), then reinstall Build 5584.
for further info on the uninstall, go here:
http://forum.parallels.com/showthread.php?t=20082 and read post number 2 by Xenos.
The operating system you previously installed within Parallels, including all settings and ownership verifications is found in a folder called "Parallels", inside your "Documents" folder. Do not erase anything in that folder during your "uninstall". I would make a backup copy of that folder just in case.
If that folder somehow did not migrate during your Leopard upgrade, find it if you have a backup of your Tiger install and get it onto your Leopard drive, in the same relative location. Parallels won't run without it.
When you reinstall Parallels, simply install the Build 5584 download as you did when running tiger. It will install the entire parallels program, and it will find your license info in the ~/documents/parallels folder noted above.
If that doesn't help, you might find some clues here:
http://forum.parallels.com/showthread.php?t=19108
Hope that helps, mjokerst