connection problem between android to ADK

Hi all,
right now i am facing a problem in this whenever i m trying to establish a connection between adk to android, so many times it's not connected. or i can say it's not connected in single time, for establishing connection i have to try to replug many time so why this is happening i m trying to figure out..can anyone have this problem or what is the option i can try to figure out.

i m my opinion accessory mode is not working but why is not working properly i dont know.

this is the link where i find may be accessory mode is not working.

Hardware :- MEGA ADK
HTC explore which have android 2.3.6
Software :- Arduino 1.0 IDE
Sketch :- demokit

USB library GitHub - felis/USB_Host_Shield_2.0: Revision 2.0 of USB Host Library for Arduino.
Sketch USB_Host_Shield_2.0/ArduinoBlinkLED.ino at master · felis/USB_Host_Shield_2.0 · GitHub

My galaxy ace (2.3.6) does not support ADK mode too but was expected to :~