error: couldn't close device: Transaction timed out

[Joe]

Hi folks!

I noticed error message as reported in title on a
Debian Jessie using a usb mobile internet dongle:
Olivetti Olicard-300, IDs are "2020:4000" after
mode switching. Product name is MTK-6225.

I've tried to upgrade both kernel version to 4.x
(from debian unstable) and libmbim-* packages
from unstable (1.12.2) debian release as well.
Dfault kernel and libmbim were linux-3.16 and
libmbim-1.10.x

Unfortunally error message above persits.
Where could be the matter?

I tested a recompiled 1.12.2 libmbim package on
a Slackware-14.0 with upgraded kernel version
to 3.19.4. Here I can use mbimcli without any
problem.
Also on this Slackware system I had same error
with old kernel version and old libmbim package,
so I thought that an upgrade would be enough to
solve also on Debian...

Could you help me looking for a solution?

Thanks in advance