cron error

[steve%prd.co.uk@localhost (Steve Blinkhorn)]

I find my /var/log/messages has this message one a regular basis:

cron: in pam_vprompt(): no conversation function

 and correspondingly in /var/log/cron:

cron[964]: (CRON) pam_authenticate failed (System error)

regular cron jobs don't run.

Is this a case of just restarting cron, or is something more sinister
going on?

-- 
Steve Blinkhorn <steve%prd.co.uk@localhost>