Possible this is problem just of Tiny editor :(
we don`t cut any information that receive from this field
Just now I perform some tests at dolphin blogs section

click enter in Tiny, it become as
<p>&nbsp;</p>

click save, after click edit again, look HTML code in Tiny
<p></p>

hehe, ok, click save again,
after click edit post again, and as result I see next
<p>&nbsp;</p>
again .. strange Tiny ...

During tests I disable all processing of see more requested params .. so you can try to perform tests too and share with results.