[Lynne]

Line 2484 is this:
($hook = vBulletinHook::fetch_hook('private_insertpm_proces s')) ? eval($hook) : false;

So, you've got a plug-in installed that uses that hook which is causing the problem. You need to disable that hack if you want to get rid of the problem. Then go read the hack thread to see if this problem has come up before and what the solution is.