They work fine with Coppermine CPUs (tested with Celeron 600) without any problems.
With Tualatin, they seem to work fine. But they often hang after reboot (either soft or hard). Then RESET button does not help and even soft-off. I have to disconnect power from the PSU (so the +5VSB power goes away) and then connect back. Then it powers up and boots just fine.
The same thing happens with multiple Tualatin CPUs (Celeron 1300, Celeron 1000A, Pentium III 1200).
Looks like a nasty bug in the BIOS but there is no later BIOS than this:
09/13/2001-i815-47B27X-JA69RT3CC-00
I've also tried 2 older versions with no change (except that one of them identified the Tualatin Celeron as Pentium III
)I also don't have a PCI POST card (only ISA) to test.