excessive boost..at idle!

Hello! 

On a rotax 914 powered plane during take off phase the red lamp goes on.

To investigate i downloaded tcu log.

There are some high boost events around  5800 rpm and 115% power. Perhaps due to overshoot and transient boost values.

but the real strange thing is that are also events that show very hight overboost (>1700 mbar) at around idle rpms (around 2200-2800) with also  throttle position at almost idle (2-8%) and wastgate around 40% opened.

this is the log with some notes on the unusual values 

log image 

in Your expertise and experience it can be a airbox pressure sensor error and there are other explanations?

in addenda: someone know what are the I or O indication on the left of every line of the log?

many thanks in advance