Here is a link to my stats page. http://boincstats.com/stats/boinc_host_graph.php?pr=bo&id=617fdb9514bc3cd23d072ef81d7e57f5

How is it possible to lose credits I rightfully earned? The only thing I can think of that could have caused this is that I detached from projects that don't use CUDA (my computers have great Nvidia cards) and I detached Seti@home because BOINCstats says they have been down for several days (so does their website), yet Seti was using my computer resources, so I turned them off until they solved their issues.

From the FAQ, I understood that once you earn credits, they can't be taken away from you, even if you detach from a project. Please explain what happened. Thank you.

This time the Orbit credits are gone from the host stats. I checked my hosts at the Orbit project and the CPIDs are correct.

As already mentioned in this message this is not a CPID problem.

The CPID of the host changes in some projects. How is this not a CPID problem?

I can't see any lost credits here: http://de.boincstats.com/stats/boinc_user_graph.php?pr=bo&id=296321aba114126f734f14a08e5cbdf9
OK, one host got somehow split, but you lost nothing. If you look at your host list, you see some credits moving to and from one host to another, but so what?
I never had the impression that host CPIDs were something good and consistent and reliable, the real CPID on the other hand is.

Example host:
CPID a830821aaf9e42acbfb4afbf040592e1 in Detailed statistics for Host ID "7397402".
CPID a830821aaf9e42acbfb4afbf040592e1 in Host details page at Orbit.
CPIDs are exactly the same.

Host has 9,786 credits at Orbit. Host got -7,806 credits on 2011-10-13 (~2000 credits from other projects).

There aren't any hosts (new or existing) where the credits moved to.

Usually the credits come back with the next host update. Could it be a problem with the exported host data?

Leiden Classical credits are not included in Combined host stats.

Example 1: Host with Leiden Classical stats and Combined host stats. This host died in late October and didn't communicated with any project since days.

Example 2: Host with Leiden Classical stats and Combined host stats. This host is an active desktop pc.

Today the Leiden Classical credits are back in the Combined host stats. With a CPID split.