changes getting clobbered--CVSREAD the culprit?

[James Hughes]

Hi all:

I have worked on two projects under cvs control, one at school(3 
developers) and my current work situation (3-4 developers). Our problem 
is that we are finding that changes are routinely getting clobbered when 
2 developers work on the same file. We have a strict regimen (I hope) of 
 always running "cvs update" before committing any changes.

The wierd thing is, on my previous project, we never lost one line of 
code. The only difference in configuration between the two projects is 
that, at my work now, we have CVSREAD set, which means that cvs update 
pulls down files read-only, and we must use "cvs edit filename" before 
working on a file. All developers have been encouraged to check if a 
file is in use by another developer (using "cvs status" or "cvs 
editors") and general we're quite paranoid about not stepping on others' 
changes. But it still seems  to happen, sometimes with quite frustrating 
results.

My question, then, is twofold: can anybody see something that we are 
doing wrong? and, what are the benefits/drawbacks of setting CVSREAD? I 
zero in on this only because, as I said, it's the major config 
difference between the two projects, one of which was problem free and 
one which is not.

Any input appreciated,
James