vSphere 5.5 - Performance chart only show the last 2 months....

Hi,

On one of my vCenter 5.5.0 (ESXi 5.5.0), the performance charts only show data from the last 2 months even though we select "last year".

I know there was an issue with the 5.1 version but I didn't see anything about the 5.5

Any idea what could cause this problem ?

Thanks.

Eric