Often Yun won't boot

I've a Yun updated with the last release that only sometimes boot, very often the Linux board hangs and is not possible to reset it (linux reset, wifi reset or power cycle).
When I load serial sketch, I've a prompt where I need to send the command "boot"

I tried to re-update, reset it (when boot), but nothing change, someone could help me please?

Thank You!

There is a potential issue with the Yun, where if the sketch is sending data to the Linux side shortly after power up, it can stop the Linux side from booting. It seems likely this may be your problem.

The issue is that there are a couple places very early in the Linux boot process where you can press any key on the Linux serial console to interrupt the boot process and enter a special boot command mode. The issue is that the serial console is the same serial port that is connected to the sketch processor. Therefore, if the sketch tries to send a bunch of data to the Linux side immediately after it starts up, there is a good chance that that data will be considered an "any key press" and stop the boot process.

Have you looked at this page? Arduino Playground - Yun

Thanks! I read the gudelines and I solved the problem, now the Yun boot correctly everytime!