I have a motorokr Z6m. In the proccess of trying to get it tethered to my comp to provide internet service to my small network. I came accross some people that said that the rokr needed to have a memory card in it for it to be recognized.
I don't have a card that will fit the phone to test that with and for me it is a secondary issue. I need the phone to supply internet service more than I need to access the storage and what not on the phone.
I don't know if this will help you but I have discovered that when I plug the rokr in I get this results
# dmesg | tail
[ 5656.467139] usb 1-2: USB disconnect, address 18
[ 5656.467146] usb 1-2.1: USB disconnect, address 19
[ 5669.135286] usb 1-6: USB disconnect, address 17
[ 5726.722665] hub 2-0:1.0: unable to enumerate USB device on port 6
[ 5727.090656] usb 1-6: new full speed USB device using ohci_hcd and address 20
[ 5727.310823] usb 1-6: configuration #1 chosen from 1 choice
[ 5727.319304] usb 1-6: New USB device found, idVendor=22b8, idProduct=2b24
[ 5727.319312] usb 1-6: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 5727.319316] usb 1-6: Product: Motorola Z6m
[ 5727.319320] usb 1-6: Manufacturer: Motorola Inc.
When I plug in the old Motorola E815 (that works) I get this
# dmesg | tail
[ 6274.821522] drivers/usb/class/cdc-acm.c: v0.25:USB Abstract Control Model driver for USB modems and ISDN adapters
[ 6275.814231] usb 1-6: USB disconnect, address 21
[ 6276.212981] hub 2-0:1.0: unable to enumerate USB device on port 6
[ 6276.524992] usb 1-6: new full speed USB device using ohci_hcd and address 22
[ 6276.745202] usb 1-6: configuration #1 chosen from 1 choice
[ 6276.746656] cdc_acm 1-6:1.0: ttyACM0: USB ACM device
[ 6276.758735] usb 1-6: New USB device found, idVendor=22b8, idProduct=2a62
[ 6276.758743] usb 1-6: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 6276.758747] usb 1-6: Product: Motorola E815
[ 6276.758750] usb 1-6: Manufacturer: Motorola, Inc.
As you can see the e815 is being recognized and assigned the 'ttyACM0' with a proper driver activated for it. But the rokr is not. So I have been trying to find the correct package/driver to access the phone with. So far I have found little information about using the rokr in linux as a usb modem.
I also read that not all of the rokr's have a linux based os in them. Don't know how true that is or how to check which os is on it.
I hope to get the issue resolved befor the month is up on the extra line I had to pay for to keep internet service.
I wish you all success in your quest.