I got similar problem with <fo:block-container /> in table cell. Having all 3 "principles" above satisfied, I got an empty table with following cell markup:
<fo:table-cell border-bottom-style="none" border-left-style="none" border-right-style="none" border-top-style="none" border="solid 1pt gray" padding="2pt" display-align="center">
As soon as I replaced block-container with its content, I got my table rendered (I tried to remove overflow attribute, but there were no effects). Btw, Fonet version is 1.0.3318.11064.