Kernel clock issue "Clocksource tsc unstable"

[Hal Burgiss]

I have a wierd problem effecting two different 8.04LTS servers (fully
updated). Their clocks stop updating. The one today said 18:05 with
yesterdays date. And it stays that way forever. The only fix is a hard
reset. This f*'s with anything that is time sensitive, so all logging
stops, remote logins don't work, various networking stuff is broke,
and so on. A PITA.

I have probably at least 6 systems on 8.04LTS, but only have this
issue only on two of them, and these are radically different hardware.
At first I suspected a hardware issue when I only had this issue with
one machine. Now I have it with 2 so I can't imagine its hardware. To
make it worse, its very sporadic. On the one system, it happens
approximately once a month. The other system is new, has been running
about 2 months, and this was the first occurence.

One message I did grab says:

 06:05:11 dio kernel: [1617517.563814] Clocksource tsc unstable (delta = 4686705598 ns)
 06:05:11 dio kernel: [1617517.573798] Time: acpi_pm clocksource has been installed.

That was during a time server sync. In exactly 6 hours (at 12:05) that
same day, the clock stopped updating, logging stopped, ssh was fubar,
and I had to physically go to the datacenter and hit the reset button
to fix it. 

There is no shortage to this problem on google, but most info sounds
like workarounds or guesses. There is at least one open bug report on
launchpad. Its labeled New from last September, which does not inspire
confidence.

So I am curious if anyone has dealt with this, fixed it and/or
understands the issue enough to offer a fix? These are both production
systems, so I'd prefer to minimize guessing. One is local to where I
am, and that is easier, but one is remote.

-- 
Hal