"Big Problem" with removable media

[Nicolas]

Hi,

I'm using FreeBSD 8-Current (as of today) and when i plug my samsung 
omnia, i have this message:

ugen7.7: <SAMSUNG> at usbus7
umass1: <SAMSUNG SGH-i900, class 0/0, rev 2.00/0.00, addr 7> on usbus7
umass1:  SCSI over Bulk-Only; quirks = 0x0000
umass1:3:1:-1: Attached to scbus3
da1 at umass-sim1 bus 1 target 0 lun 0
da1: <  > Removable Direct Access SCSI-0 device
da1: 40.000MB/s transfers
da1: 7680MB (15728640 512 byte sectors: 255H 63S/T 979C)
GEOM: da1: partition 1 does not start on a track boundary.
GEOM: da1: partition 1 does not end on a track boundary.
(da1:umass-sim1:1:0:0): Synchronize cache failed, status == 0x4, scsi 
status == 0x0

My computer frezees until i unplug the device.
What's wrong ?

Thanks in advance,
Niko.