[GRASSLIST:6366] i.maxlike does not read sig file

[Martin Wegmann]

Hello, 

I tried an unsupervised classification with i.group, i.cluster and i.maxlik. 
However i.maxlik prompts that it can't read the signature file. 

I read the Image Processing tutorial and the help files but cannot find what I 
did wrong.

procedure:

i.group group=all_img subgroup=all_img_sub 
input=mask_evi_250m16d_recode.1,mask_evi_250m16d_recode.2, .....

i.cluster group=all_img subgroup=all_img_sub sigfile=all_img_sig classes=100

i.maxlik group=all_img subgroup=all_img_sub sigfile=all_img_sig 
class=all_img_class reject=all_img_rej

i.maxlik prompts:
Can't read signature file all_img_sig

Any idea where I went wrong?

thanks in advance, cheers Martin

P.S.: GRASS 6 debian rep.