Any USB device automatically gets connected as read-only which means the adb server and Eclipse won´t see the device when you plug it in.

This post gives a little information on how to fix it.

The idea is to create a rules file that listens for the Android device and sets the permissions differently. The rules are all located under /etc/udev/rules.d. So in detail,

Create a new rule for Android devices

vi /etc/udev/rules.d/99-android.rules

Add the following code

SUBSYSTEM=="usb",SYSFS{idVendor}=="0bb4",SYMLINK+="android_adb",MODE="0666"

And run

udevcontrol reload_rules

Plug it in and it should work.