Yes. I'll give an example reason: When I take a photo of myself, someone else has to take it. But it is still my photo. Well no I have a wireless shutter release so not anymore.. but
So I rarely vote. I'm biased towards my own photo and think it's the best always because I know what I was trying to show/express and the rest of the photo's don't "speak to me" as strongly. But also because I've never been an art critic and rarely find one photo that I like better than any other. And also, at work, not all the photos show up so I rarely see all the entries.
I also have a problem on what to base your vote on. The quality of the picture - that seems unfair to those with cheaper cameras. The technical aspect of the picture - again unfair to non-photographers or people who haven't studied or even know there are technical aspects of photo taking. The ability of the picture to match the theme - this might be the 'fairest' option, but how many people use this method to vote?
I tend to fall into the 'the ability to match the theme' category. This usually leads me to my own photo (which isn't always the best in terms of quality or technically) or another persons that also falls along the same line.
I'm going to call attention to Smart Guy's picture. He clearly doesn't have the best quality or a technically sound picture, but he took a very creative "action" shot. For me that's what this competition should be about. The most creative shot you can take while still meeting the theme.
Don't get me wrong, I think all the shots meet the theme, but some are more straightforward than his. They are much higher quality and much more technically sound (check out that 'rule of thirds' on Brigg's pic) but the ones that "speak to me" are the more creative ones.
Hopefully I've made my point on why I have such a hard time actually voting. We have some really great photographers here and I would love to be able to spend more time taking pictures. I love having these comps though so lets keep it going!