Change properties with treehouse?

Double clicking on a component in Treehouse brings up a properties list, which you can edit.  My question is, how does this information get saved back to the part file?  If I change a value and save and exit Treehouse, and then open up the part, the property that I changed in Treehouse did not change.  But if I open up Treehouse again, it shows that the property of that part DID change.  Doesn't make any sense.  What am I missing?