sudo skips passwd prompt

[Joe Zlomislic]

Hi,
we are using sudo 1.5.3 on a Sun V480 solaris9 server  and up until recently, sudo worked fine.  But a couple of days ago sudo stopped working properly.  I have a sudo group in the groups file and an entry in the sudoers file for the %sudo group set to ALL for root similar to our other servers which work fine with the same config.

The problem is, when I login as joeuser and run 'sudo' it shows the Password: prompt but skips over it and goes back to my joeuser prompt without becoming root.  It's like there is an automatic line feed that skips over the password prompt.  Has anyone seen this type of behaviour?

any help is appreciated...
thanks,
Joe.