Check out
http://apps.facebook.com/rssgraffiti/ for cms-to-fackbook. Then use a facebook app for fb-to-twitter. I use rssgraffiti on my vb4 cms.
If your article image doesn't show up in fb, try hand coding the img tag. I keep some generic HTML in a text file on hand to do this quickly (see below):
Code:
<div style="display: block;float:left"><IMG SRC="http://www.MyDomain.com/images/news/zzzzzzzzzzzzz" alt="zzzzz"></div>
<div style="display: block;float:left"><IMG SRC="http://www.MyDomain.com/images/news/zzzzzzzzzzzzz" alt="zzzzz"></div>
<div style="display: block;float:left"><IMG SRC="http://www.MyDomain.com/images/news/zzzzzzzzzzzzz" alt="zzzzz"></div>