Earlier today I discovered that Feedburner was hating on my syndication feed. I was getting this error:

XML Parsing Error: xml processing instruction not at start of external entity. Line Number 2, Column 1:

It took me a while, but some research “turned up an answer”:http://wordpress.org/support/topic/21795#post-123962 – apparently there are some plugins out there that push all the code on every page down a line. For syndication feeds, this is a very bad thing, since they are built on XML code and the XML identifier is required to be the first thing a reader sees in order for it to work. In my case, it was probably a plugin that was pushing everything down so I started shutting plugins off.

I’m chagrined to discover that my feed has probably been very unhealthy for several days now. I discovered two plugins that were creating problems, one of which I’ve had activated for a couple of weeks. “Category Converter”:http://armenianeagle.com/plugins was the first, so if I find I need to use this one again in the future, it will get activated, used, and turned right back off again. The other was one I’d wanted to try out because I’ve noticed that some of my posts are getting scraped and posted elsewhere. Most of these have links back here but are being credited to those sites’ owners. I’m not all _that_ upset about it, but it _is_ kind of annoying and discourteous. So, I’d decided to give “Antileech”:http://redalt.com/Resources/Plugins/AntiLeech a try today. Except – this plugin _also_ bumps everything down a line, thus rendering my feeds essentially dead. So, a no-go to that one, as well.

Odd thing is this – I’m subscribed to my own feed, primarily to monitor its health. Everything has been coming through just fine every day, albeit sometimes hours after the fact, but so long as they were coming through, I wasn’t all that concerned. So, I’ve no idea why, with my feed essentially being invalid, I’ve still been getting updates on a regular basis. Those of you who subscribe to my feed – have you been getting daily updates? And maybe someone who knows and understands XML and RSS coding a little better than I do can explain to me why the feed can be invalid and yet subscribers can still receive updates. I’m all ears.

So, lesson to the wise – every time you install and activate a new plugin, check your feed immediately and make sure it’s still working. Some plugins may not like your syndication all that well.