Empty password used - try 'cvs login' with a real password

[simmo]

Guys,

One member of my team keeps getting this message:

Empty password used - try 'cvs login' with a real password
cvs.exe [tag aborted]: authorization failed: server denzel rejected
access to d:/Engineering/CVS for user davidb

It usually happens when david is trying to tag code, but we have a
feeling that it has happened when running other CVS commands too. We
can get round the problem by scrubbing everything in his working
directory and checking everything out again, but this is far from ideal
as we have a very large code repository so it takes an anoying amount
of time to keep on doing this.

Has anyone any ideas what he could be doing to get into this state?

One thing that may be worth mentioning is that we are using netbeans
and performing some of the updates and commits from there rather than
the command line, but everyone in the team is doing this, so I can't
really see that being the problem.

TIA

Simon