Acrobat X

I want to open PDFs and save them as HTML using Applescript.
It works in Acrobat 9 except I occasionally get random errors for no obvious reason.
The same code in Acrobat X doesn’t work and I can’t find the new syntax if it exists.
Here’s what works in 9 (sometimes)…

tell application “Adobe Acrobat Pro”
open file (defaultFolder & “:Source.pdf”)
save front document to file (defaultFolder & “:Temp.html”) using conversion “com.adobe.acrobat.html-3-20”
save front document to file (defaultFolder & “:Temp.txt”) using conversion “com.adobe.acrobat.plain-text”
close front document saving no
end tell

The text conversion works in X but the HTML conversion generates an error.
It returns “document 1 doesn’t understand the save message.”

Alternatively, is there a better way to do this. A command line tool to convert PDF to HTML would be great!

Thanks.

Model: MacBookPro 15" i7
AppleScript: 2.2.1
Browser: Safari 536.10
Operating System: Mac OS X (10.7)

The html conversion is named “com.adobe.acrobat.html” in Acrobat X.

Yes, tried that… didn’t work!
Didn’t get an error message. Script continued to next step but didn’t create anything.
Took (apparently) zero time to I don’t think it even tried.
I think it must be an Acrobat bug. I’m using v 10.1.3. Piece of junk!