asterisk users - Aug 2005 - txfax on strike while rxfax works flawlessly

Hello,
I have installed SpanDSP and the apps txfax an rxfax. Unfortunately I am 
having problems sending faxes. I only get cancelled transfers. I am 
trying to send a fax to a ISDN card connected to a zap channel.

I am using following call file:
-------------------------------
Channel: ZAP/g1/25
MaxRetries: 0
WaitTime: 20
Application: txfax
Data: /tmp/lVD3wy.tiff|caller


Asterisk shows:
---------------
     -- Attempting call on ZAP/g1/25 for application 
txfax(/tmp/EmailToFax-lVD3wy.tiff|caller) (Retry 1)
     -- Requested transfer capability: 0x00 - SPEECH
   == Primary D-Channel on span 2 up for TEI 64
        > Channel Zap/2-1 was answered.
        > Lauching txfax(/tmp/lVD3wy.tiff|caller) on Zap/2-1
Urgent handler
DIS with final frame tag
In state 10
Start tx document
CFR with final frame tag
In state 4
Start tx page 0
Start tx page 1
XCN with final frame tag
In state 14
     -- Hungup 'Zap/2-1'
Aug 13 13:43:55 NOTICE[11332]: pbx_spool.c:239 attempt_thread: Call 
completed to ZAP/g1/25


The tiff file I am using I have received and saved with rxfax... So I am 
reasonably sure that it has nothing to do with the image file. 
Unfortunatly the messages txfax prints do not tell me anything at all.

Can anybody help me with this?

Cheers,
Arik