I was a bit fed up to see eBay's webslice feeds going up and down all the time. So I launched both MSIE8 and Firefox and loaded directly a webslice feed into both browsers.

http://ie8.ebay.com/feedclips/feed.php?item=330217578758&country=0

To my big surprise, MSIE8 could load it while FF3 's request was still triggering a server error. Then I launched Opera and Safari. Then I decided to make FF3 spoof  my MSIE8's User-Agent String.

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; (R1 1.5);
.NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648;
 .NET CLR 3.5.21022)

Here are the results, of course with an empty cache:

  • MSIE8: works fine
  • FF3, standard UA string: server error
  • FF3, spoofing MSIE8 UA string: works fine
  • the one above, back to standard FF3 UA string: server error again
  • Opera 9.23: works fine
  • Safari 3.0.4: server error

There are only three possibilities here:

  1. eBay is filtering out webslice requests coming from Safari because of Webclips and Firefox3 because of my webchunks extension (who said conspiracy theories again ?)
  2. eBay PHP developers just suck big time and this feed.php code is extremely buggy...
  3. eBay webslices feed cannot stand the load or something ; yeah, not a very plausible hypothesis but I needed to leave an excuse to eBay developers

Whatever is the cause for that, I find it rather lame that the number 1 online proof of concept of Microsoft webslices is totally unreliable and unable to update webslices most of the time. Hey, it's only eBay after all. If you add to that the fact that it's harder to put ads in a webslice because of the size of a webslice, I'm not sure webslices are going to be a big hit...

Update: in fact they're not filtering. It's really a server issue, but strangely it affects more "alternate browsers" than MSIE8. It's often the case MSIE8 has no problem updating a webslice when all other browsers can't do it.