I have a Sony DSLR and a NIKON Coolpix. In Fedora 16 gnome i could connect both cameras. In XFCE i only can connect Sony.
Here is the portion of the log. First i tried with NIKON then with SONY. The interetsting part with NIKON is that it stops after it says Serial Number 0.
Apr 16 11:34:49 localhost kernel: [ 165.627873] usb 1-3: New USB device found, idVendor=04b0, idProduct=0314
Apr 16 11:34:49 localhost kernel: [ 165.627877] usb 1-3: New USB device strings: Mfr=1, Product=3, SerialNumber=4
Apr 16 11:34:49 localhost kernel: [ 165.627879] usb 1-3: Product: NIKON DSC COOLPIX L18-PTP
Apr 16 11:34:49 localhost kernel: [ 165.627882] usb 1-3: Manufacturer: NIKON
Apr 16 11:34:49 localhost kernel: [ 165.627883] usb 1-3: SerialNumber: 0
Apr 16 11:35:46 localhost kernel: [ 222.375662] usb 1-3: USB disconnect, device number 4
Apr 16 11:36:07 localhost kernel: [ 243.393032] usb 1-3: new high-speed USB device number 5 using ehci_hcd
Apr 16 11:36:07 localhost kernel: [ 243.559178] usb 1-3: New USB device found, idVendor=054c, idProduct=0320
Apr 16 11:36:07 localhost kernel: [ 243.559181] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Apr 16 11:36:07 localhost kernel: [ 243.559184] usb 1-3: Product: DSLR-A300
Apr 16 11:36:07 localhost kernel: [ 243.559186] usb 1-3: Manufacturer: Sony
Apr 16 11:36:07 localhost kernel: [ 243.559188] usb 1-3: SerialNumber: 5D4B200D2C70
Apr 16 11:36:07 localhost kernel: [ 243.606049] Initializing USB Mass Storage driver...
Apr 16 11:36:07 localhost kernel: [ 243.609682] scsi6 : usb-storage 1-3:1.0
Apr 16 11:36:07 localhost kernel: [ 243.609810] usbcore: registered new interface driver usb-storage
Apr 16 11:36:07 localhost kernel: [ 243.609812] USB Mass Storage support registered.
Apr 16 11:36:08 localhost kernel: [ 244.626091] scsi 6:0:0:0: Direct-Access Sony DSLR-A300 1.00 PQ: 0 ANSI: 0 CCS
Apr 16 11:36:08 localhost kernel: [ 244.627073] sd 6:0:0:0: Attached scsi generic sg2 type 0
Apr 16 11:36:08 localhost kernel: [ 244.631951] sd 6:0:0:0: [sdb] 7962192 512-byte logical blocks: (4.07 GB/3.79 GiB)
Apr 16 11:36:08 localhost kernel: [ 244.632592] sd 6:0:0:0: [sdb] Write Protect is off
Apr 16 11:36:08 localhost kernel: [ 244.633201] sd 6:0:0:0: [sdb] No Caching mode page present
Apr 16 11:36:08 localhost kernel: [ 244.633205] sd 6:0:0:0: [sdb] Assuming drive cache: write through
Apr 16 11:36:08 localhost kernel: [ 244.636574] sd 6:0:0:0: [sdb] No Caching mode page present
Apr 16 11:36:08 localhost kernel: [ 244.636579] sd 6:0:0:0: [sdb] Assuming drive cache: write through
Apr 16 11:36:08 localhost kernel: [ 245.070603] sdb: sdb1
Apr 16 11:36:08 localhost kernel: [ 245.230082] sd 6:0:0:0: [sdb] No Caching mode page present
Apr 16 11:36:08 localhost kernel: [ 245.230088] sd 6:0:0:0: [sdb] Assuming drive cache: write through
Apr 16 11:36:08 localhost kernel: [ 245.230092] sd 6:0:0:0: [sdb] Attached SCSI removable disk
Apr 16 11:36:14 localhost kernel: [ 250.416095] libfcoe_device_notification: NETDEV_UNREGISTER lo
Apr 16 11:36:18 localhost kernel: [ 255.186470] usb 1-3: USB disconnect, device number 5
Apr 16 11:37:54 localhost kernel: [ 351.174759] libfcoe_device_notification: NETDEV_UNREGISTER lo