Could not write /var/run/utmp: Interrupted system call

[Jonathan Martin]

Hey everyone. Has anyone ever seen this when starting screen, or  
detaching from screen:

    Could not write /var/run/utmp: Interrupted system call

And when creating new windows:

    Could not write /var/run/utmp: No such process

Utmp is one of those unix-y things I never bothered trying to  
understand, right up there with sendmail.cf, and nis+. But my Spidey  
Sense tells me that years ago was a writable file, but maybe now it's  
safely managed by a daemon. That's just a bad guess though.

Oh I should mention I haven't rebooted since this started happening.  
I can still attach to the 2-week old screen session (which is why I  
haven't rebooted -- I have apps I don't want to end quite yet). I'm  
sure rebooting will fix it. I'm mostly just curious, especially since  
I've used screen obsessively for almost a decade.

Any ideas about what's going on would be entertaining. Thanks.


Setup:
    Dual 600mhz PIII
    Ubuntu 5.10
    Kernel 2.6.12-9-686-SMP
    Screen version 4.00.02 (FAU) 5-Dec-03