I came over an unusual case while "trawling" through some Bamstats.

One Bamstat for an active GPUGrid-host is still related to an older ID of the same kind under a previously installation. The BOINC manager 6.6.10.4 keep the new Host ID right. but the detailed stats at the Host list menu shows an inactive host: - This host is not active, therefore limited details are available -

Might be have been caused by the fact that I still use the same host-name. And the database might have made some kind of confusion under maintenance ? However all other clients on the same host have got a new Host ID.
- How can this sole zombie-host be removed ?
Or is it a Bam database error ?
- How can I get the correct Host ID of the active one whithout removing the all single host installation and risking that the "zombie"
reappears once again ?

Did you install BOINC after reformatting or re-installing your OS? That could cause it to have a different host ID. This isn't really a problem with BOINCstats, but the projects; you will have to go to the projects you've crunched with this host and merge them. Unfortunately, some projects don't allow merging (or they may not be able to merge if something major is different) so you may not be able to take care of it completely. I have a number of such hosts under my detailed host stats; I don't let them bother me too much.

Thx to Noderaser! As you guessed, this happened after an OS-reinstallation.