Hi there,

Is your Device drivers has been installed properly? well can you open your droids drive from your PC? But couldn't debug your with your Android Device? It gives an permission problem or few question marks(?????) within Eclipse
environment? Then this guide is for you. Now you can simply resolve it.

Copy the bold colored number.

[harshadura@localhost rules.d]$ lsusb
Bus 007 Device 002: ID 04e8:685e Samsung Electronics Co., Ltd 
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 004: ID 09da:000a A4 Tech Co., Ltd Port Mouse
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 014: ID 1c9e:6061  
Bus 005 Device 002: ID 08ff:2580 AuthenTec, Inc. AES2501 Fingerprint Sensor
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
[harshadura@localhost rules.d]$ 

[harshadura@localhost /]$ cd /etc/udev/rules.d/
[harshadura@localhost rules.d]$ 
[harshadura@localhost rules.d]$ ls
10-vboxdrv.rules  56-hpmud_support.rules       70-persistent-cd.rules   85-pcscd_ccid.rules           90-hal.rules               99-fuse.rules
40-hplip.rules    60-fprint-autosuspend.rules  70-persistent-net.rules  90-alsa.rules                 91-drm-modeset.rules       99-gpsd.rules
51-android.rules  60-sysprof.rules             80-kvm.rules             90-alsa-tools-firmware.rules  97-bluetooth-serial.rules
[harshadura@localhost rules.d]$ 
[harshadura@localhost rules.d]$ vi 51-android.rules 

Paste the previously copied number here.

SUBSYSTEM=="usb", SYSFS{idVendor}=="04E8", MODE="0666"

Save the file properly.
Finally, restart the system.

Cheers!