Hi,
Okay now I get it, I have to 'umount /dev/sdb1' then insert 3rd USB so it scans again then '/dev/sdb1' is now mounted at USB Storage but '/dev/sdbc1' is now the problem.
To make it visible, you have to do it again:
• 'umount /dev/sdc1'
• insert 4th usb
• now sdc1 is available at USB storage page but sdd1 is now the problem.
any idea what triggers the mount so I wont do umount everytime and no need to insert another USB?
thanks everyone.