This issue has existed for some time now. It's very frustrating.
Then there's also the fact that curved text behaves in a very different fashion for Parcel Labels and for General Curve Labels. That's pretty irritating, too.
I hear rumors of a "more-robust labeling engine" in the works. I greet this news with ambivalence, because the current label design is so bad I'm glad they're reworking it, but I'm afraid of how many versions it will take to get a "more-robust labeling engine" working...
(not to mention, we'll probably have to redo all our label styles again... boy those styles are a HUGE time-sink...)