CCleaner found those registry issues:

1)ActiveX/COM Issue InProcServer32\%SystemRoot%\System32\eapa3hst.dll
2)ActiveX/COM Issue InProcServer32\C:\Windows\System32\eapahost.dll
3)ActiveX/COM Issue InProcServer32\%SystemRoot%\System32\eapa3hst.dll
4)ActiveX/COM Issue InProcServer32\%SystemRoot%\System32\eapa3hst.dll

I don't feel safe to delete them since they are dll files. Any help appreciated.

I have the Exact same 4...
What do or did they go to ?.
This post has not been answered in 2 months...Wow!

If the file(s) dont exist, it should be safe to delete the registry entry. Just make a backup when CCleaner prompts you to. If I recall, I searched for this a while back and found that the files are related to the Extensible Authentication Protocol for a wireless network.

And I have the exact four as well. I seem to remember that after a fresh XPHSP3 install these were the only issues found (after I had cleaned up a few obviously bad entries). I shall wipe these now. Well, soon.

That's exactly right. These only came up after updating TO WinXP SP3.

Well, they've gone, with no ill effects. Yippee. a clean registry scan!

They seem to be related to some anti virus program or another, says a quick google search. I'd say tick them and back them up and clean them, if theres a problem just restore them (I think the registry cleaner needs an ignore list, tbh.)

I think so too!!!

So long as it was in a simple format without all that Exclude1, Exclude2, etc., stuff so the ignore list could look something like:
HKCU\Software\Some App\Some Settings
HKLM\Software\Some Other App\Some Other Settings