I'm using rss intensively on several website providing them, i use internet explorer latest revision on windows XP with the latest updates.
Since 18th december i got rss error on gog.com, is there something i can do ?, or is there something that has change on the website ?
thank you for the help.

I've also discovered this. The last entry is "GOG.com holiday surprise: Tex Murphy 1+2 for free!". When I try to reload it, I get a "Live bookmark failed to load" message (with Firefox).
Let's hope they will fix it now, with the holidays over...

I'm pretty sure the trouble is the & in Might & Magic. XML (which is the basis of RSS and Atom, both the most common formats used for web feeds) doesn't accept plain-text ampersands, because it's a special-use character it has to be encoded or the XML won't be valid (thus making any apps trying to read the XML crap out).
The entry directly after "GOG.com Holiday Surprise: Tex Murphy 1+2 for FREE!" is "Weekend promo: Might & Magic series up to 50% off", so it's logical that the last successful read of the XMl feed was right before that M&M entry was added. Because the feed reader caches anything you've already fetched, you can still read up to that point.
The solution: we try to get the GOG team to fix the entry, switching the plaintext & to & (or the & to & if it already is escaped but needs to be double escaped).

Valid point.
I've just checked some older MM- or HOMM-related news, and there they wrote "and" instead of "&", probably exactly because of this incompatibity.

Problem solved thank you :)