[Doitsu]

I'm trying to create interlinear epubs for language learning purposes. I created an .xhtml file with with a special table style based on Japanese Ruby text and converted it with Calibre. The output looks OK with the Calibre viewer and the Firefox epub plugin, but Adobe Digital Editions shows only the body text and not the blue interlinear translations below it.
Also when I try to upload it to my IPhone with Stanza, the formatting is not displayed correctly.

Therefore I'm wondering if the epub standard actually supports xhtml table and/or Ruby tags?

Can someone who has an actual hardware epub reader test whether the small test epub in the attachment is displayed correctly? (You should see black Spanish text with small blue English translations below.)

Also I'd appreciate any ideas regarding alternative markups for displaying interlinear text. (I included the not very sophisticated source .xhtml file in the attachment.)