MM 0.6.0 conflicts with USB GPS device?

["W. Martin Borgert" <debacle debian org>]

Hi,

ModemManager 0.6.0 (02ddf9a6732fba19c248d83cadfb56452c815091) seems to  
be confused, when a USB GPS device is connected.
The GPS device always sends permanently data in form of ASCII strings at
4800 bps.
It does not answer to any commands, such as ATI.
Unfortunately it idenfies itself as a USB serial adaptor, so ModemManager
rightly tries to find a modem there.
But ModemManager should detect, that this is not a modem and let the device
alone.
Instead it tries to identify the poor device again and again, which
prevents the legitimate GPS software to access it.

The GPS device as shown by lsub:

ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

The output from MM:

modem-manager.debug[1577]: <debug> [1370004683.185636]  
[mm-at-serial-port.c:334] debug_log(): (ttyUSB0): <-- '\0'
modem-manager.debug[1577]: <debug> [1370004683.189633]  
[mm-at-serial-port.c:334] debug_log(): (ttyUSB0): <-- '\0'
modem-manager.debug[1577]: <debug> [1370004683.214500]  
[mm-at-serial-port.c:334] debug_log(): (ttyUSB0): <-- '\0\0'
modem-manager.debug[1577]: <debug> [1370004683.217178]  
[mm-at-serial-port.c:334] debug_log(): (ttyUSB0): --> 'AT+GCAP<CR>'
modem-manager.debug[1577]: <debug> [1370004683.919845]  
[mm-at-serial-port.c:334] debug_log(): (ttyUSB0): <-- '\0\0\0\0\0\0\0'
modem-manager.debug[1577]: <debug> [1370004683.945792]  
[mm-at-serial-port.c:334] debug_log(): (ttyUSB0): <-- '\0'
modem-manager.debug[1577]: <debug> [1370004683.986895]  
[mm-at-serial-port.c:334] debug_log(): (ttyUSB0): <-- '\0'

Does somebody have an idea how to solve the problem?

Thanks in advance!