[PD] logitech webcam and GEM

[altern]

hi

i am trying to use a USB webcam with GEM on my IBM laptop with Ubuntu 
Studio but pd gives me an error

error: failed opening device '/dev/video0'

the same camera runs perfectly on the same laptop under XP and also on 
my desktop machine with Ubuntu Studio. All using the same patch and same 
versions of PD and GEM.

The camera is a logitech quickcam communicate STX
PD 0.39.3 extended-rc5
Linux r2d2-desktop 2.6.20-16-lowlatency #2 SMP PREEMPT Fri Aug 31 
00:58:46 UTC 2007 i686 GNU/Linux

The camera seems to be recognised, if i plug it on i can see the 
camera's blue light flashing and dmesg gives this :

[27776.980572] ubuntu/media/gspcav1/gspca_core.c: USB SPCA5XX camera 
found.(ZC3XX)

same message as in the desktop machine.

Comparing the PD output from both machines i can see that after saying

- GEM start rendering
my desktop says :
- v4l::thread starting
but the laptop says:
- error: failed opening device '/dev/video0'

i searched with synaptic for v4l and compared all stuff installed in 
both machines just in case i was missing some library in the laptop, but 
it is exactly the same in both...

my bet is that some module is missing, but i dont know which ones might 
be as i havent mess around with modules very much so far, i am comparing 
the lsmod from the desktop and laptop at the moment, there are few 
differences but i dont really know where to start from, any one has any 
idea?

thanks!

enrike