I finally found something that does a decent job of converting double
columned books:
http://www.filetransit.com/files.php...erter_Download
I am smitten with this prog. It.s free for the first 30 days. With some limitations
I converted 499 double column books to pdb with this in about 5 minutes. They look acceptable, Calibre turns them into any type of format you want in little time.
So while waiting for a plug-in for calibre that does this.....