As specified in bug #42578, this is a kernel bug.
It seems that kernel from 2.6.13 up ti 2.6.15 have a broken pp support.
I have compiled a custom 2.6.17 kernel, and my UMTS modem is working again.
I think now all we have to do is wait for ubuntu to have a 2.6.16+ kernel. I suppose it will be ok with edgy (2.6.17 kernel)
As specified in bug #42578, this is a kernel bug.
It seems that kernel from 2.6.13 up ti 2.6.15 have a broken pp support.
I have compiled a custom 2.6.17 kernel, and my UMTS modem is working again.
I think now all we have to do is wait for ubuntu to have a 2.6.16+ kernel. I suppose it will be ok with edgy (2.6.17 kernel)