I have a Nexus 4 with Android 4.3 and I am trying to connect the device to a computer with Windows 7 64bit.
I installed the latest drivers and the latest adb>
I was able to solve this one by following the steps listed here:http://forum.xda-developers.com/showthread.php?t=2247471
delete the computers adb key: rm /data/misc/adb/adb_key on device
(I have no idea if in case of multiple authorized computers the additional keys are in a new line of the file or if they are in new files. I have only 1 computer.)
stop all adb processes "killall adb" in linuxoids and "taskkill /IM adb.exe" in windows or simply the taskmanager in both.
restart the phone
toggle usb debugging off and on
connect
use adb
click authorize