[vdr] GRAB .... doesn't grab ! vdr-1.3.37

[mc8647tv at mclink.it]

I have a Suse 10 installation, with VDR 1.3.37 with no patches but only a couple of plugins. 
Two cards, a Nexus FF sat card and a DVB-T card. Nexus firmware is the latest experimental on Suse site.

If I issue a GRAB command the file I get is "empty", blue. in Jpeg it's only  kb, in PNM is a bit more but it contains (apart the header) all the same char!

The command I issue is:
frank at linux:~> telnet localhost 2001
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 linux SVDRP VideoDiskRecorder 1.3.37; Wed Mar  8 10:35:03 2006
grab image.pnm pnm
250 Grabbed image image.pnm pnm

In the log I get:
Mar  8 10:35:03 linux vdr[4379]: connect from 127.0.0.1, port 1992 - accepted
Mar  8 10:35:21 linux vdr[4379]: grabbing to image.pnm (PNM 100 924 576)
Mar  8 10:35:29 linux vdr[4379]: closing SVDRP connection


I have no access to the console since the PC is 1500 km from me !!!

Any clue ?

Francesco