Hi frank14612,
You can find the latest version here:
http://www.by-smart.com/epubstar/epubstar_cn.html.
I didn't try the last version, but I have had the same problem: not working with Win7 Home Premium 64-bit.
Better than Calibre you can use Apache Open Office with Writer2Xhtml (here
http://writer2latex.sourceforge.net/). If you don't use AOO it is a big prog to install, but I think it deserve it.