mulitpart boundary discrepancy

I'm doing a file upload via cgi.
The CONTENT_TYPE specifies a "boundary=" value that begins
with a bunch of ---- chars and a number after that.
When i actually retrieve the rawdata from stdin the
boundary marker that is in that data is 2 chars shorter,
2 of the '-' chars are always missing. Is that a known
problem, or is there some weirdity i dont know about that
you need to account for?

ie:
CONTENT_TYPE...
boundary=-----------------------------6558586991583571043559301039
but actual embedded boundary line is
"---------------------------6558586991583571043559301039"
2 '-' chars are missing in the actual stdin data.
Thanks
Eric

Eric