Branch tag disappeared in CVS

[Madhavi]

We have a branch B384. On this we have two more branches B3841 and 
B3842. Development is going on B384. It was working fine. But today 
suddenly when we did update on one folder in B384 branch, that branch 
tag is disappeared on that folder and output says 'missing file'. But 
B3841 and B3842 are existing. How can this happen? Any idea how to 
resolve this.

This is second time it happened like this. We are restoring previous 
day's backup and committing changes again which is a painful job.

We are using CVS 1.10 on Linux as server and WinCVS 1.2 as client.

Thanks & Regards
Madhavi