flexfax: Sending tif-Files?

[Erwin Kaiser <ekaiser@snafu.de>]

Hallo list!

I tried to send a formerly received fax by:
"tiff2ps fax.tif | sendfax -n -d #########"
but recipients received distorted faxes. 
("sendfax -n -d ######### fax.tif" hadn't worked as well)
Is there any obvious error in my commands?
I'm running HylaFax 4.0pl2.

Any ideas welcome! TIA

..........Erwin