how to customize pcl-cvs to ignore empry diretory.

[Liang Wang]

>From PCL-CVS info:
`Need-Update'
     Either a newer version than the one in your source is available in
     the repository and you have not modified your checked out version,
     or the file exists in the repository but not in your source.

But if I check out source code by using -P optioin, all empty
directories are marked as Need-Update when cvs-examine.

How can I hide those directories in *cvs* buffer?