I use intraVnews (www.intraVnews.com) to read RSS feeds.  It's free, and most importantly, it's integrated into Outlook.  However, I was having trouble getting intraVnews to read my blog's RSS feed.  I emailed intraVnews support (which is VERY good) and found out that intraVnews DOES have a problem with some dasBlog feeds.

The issue is that intraVnews sends an HTTP HEAD request to the RSS feed first, to see if it has changed.  A HEAD request is just like a GET, except that only the HTTP headers are returned.  Well, dasBlog uses a web service (.ASMX) to render the XML.  ASP.NET doesn't allow HEAD requests to ASMX files and will error.  If you have customErrors on (I think this is the default for dasBlog?), instead of a 500 internal service error, you get a 302 Found -- a redirection to an error page.  intraVnews then decides to throw this out.

Just by turning customErrors off in the web.config, the normal HTTP error will be returned, and intraVnews treats this just fine.  Thanks to intraVnews for pointing this out, and Rex Swain, for his cool HTTPView page, which lets you see exactly what's coming back in an HTTP response.