Sorry to bother, but someone else reported having this problem and it seemed to be fixed remotely, so here goes:

Got two comps up and running. One works on PrimeGrid/Chess/SETI and the other works on Einstein@Home. PrimeGrid/Chess/SETI are all being reported successfully to my account (Dreamfall). Einstein@Home is not being reported on "my detailed stats," however when I go to hosts and look at the computer working on Einstein@Home, it has Einstein stats. Upon further comparison, the CPID numbers of the hosts are different! Help please

This is in the FAQ.

CPIDs only sync up if there are hosts that are common between them the projects. The email addresses used must be identical too.

On the host that is doing Einstein only, attach it to PrimeGrid or Chess960 (or SETI, but the other two have shorter WUs) and the CPIDs will sync up after a few updates. The host doesn't need to do any work for those projects, it just needs to be attached to one of them, so you can set it to 'no new work' as soon as you attach it.