Just tried that Umbrella tree and yup that measures fine for me too.
Can you try EU_Shrubs (SH10_Populus_Tremula) and any of those. They are very small.
I'm getting a message of 'obsolete data format found ---please resave file' on all the max files from the Shrubs set.
I did some tests and it seems to depend on the library, some are ok while others pop up with this obsolete message and are the wrong scale.