Bug moving a character with onscreen Joystick prefab

Hello

I have been working in my first game, in it I move my character with an Onscreen Joystic Prefab I imported from the Standard Assets (Mobile).

I had to use the C# translated version of Penelope's Joystick script made in javascript (C# version: http://www.chrisdanielson.com/tag/joystick-js/)

It works fine but only sometimes.

Thats the problem, sometimes it works fine and sometimes it has a bug.

The bug occurs while I am using the joystick to move my char and if I touch the screen my char stops and If quickly I try to move it again with the joysticks It doesn't work correctly. After that if I stop touching the screen for about 1 second and move again my char with the joysticks it works fine again... yeah, unless I touch the screen in another position.

And as I said before sometimes it happens on my device (htc incredible s) and sometimes dont. I tried it in another device (samsung galaxy fame) and there it seems like it works without problem.

Well thats it, hope you can help me! Thanks!