CVSNT slow when exporting

[Marty]

When we try to export code by tag out of CVSNT (using Tortoise), it
often takes an extremely long time.  Many times we'll just cancel the
command, then try again.  Sometimes it goes faster than other times.

Do you know why that would be?  I'm thinking it has to do with CVS
having to go through the deltas to acquire by tag.  Any ideas on how
to speed it up?  Thanks  --Marty