Unstable Mega board with USB connection

[Blodstrupmoen]

My Arduino setup with USB connection is very unstable. It gives connection error every 2-3 minutes, and connection failure aprox. one each hour. There is no activity on input/outputs this periode. Do anyone have a solution for this. As it is now it is unusable.

[dreambox]

Did you solved this problem?
I have the same but not every few minutes but every 1 or 2 days.

I have 6 Mega and randomly it get the connection error

[Blodstrupmoen]

It is not solved, i switched to ethernet so no problems anymore.