Comment 7 for bug 491275

Thank you for your answer, John. After removing ModemManager's configuration files with synaptic, the problem still persist. To avoid the use of KdeprintFax, I used this command in a console:
/usr/bin/fax DEV='ttyS1' PAGE='a4' send 'XXXXXXXXX' 'fax.ps'
Where "XXXXXXXXX" is the fax number and fax.ps is a postscript file. The problem is the same.