Line Spacing Curiosity

I've only recently realized that I am apparently the only person who cannot use the Enter key to make single line breaks. Whenever I hit the enter key, it automatically inputs a

double line break, as seen here.

Is there something that would explain this?

Maybe a really fast finger?
Testing
It puts single line
breaks in for me.

That's pretty strange, but I'm sure it's a simple fix.

Hmm...
Now, I'm using FF, and its obviously fixed.

Apparently IE is the cause.

Probably. IE is the cause of many internet related curiosities.

I've tried going back to IE when they came out with the IE 7 beta, but Firefox is just better. I'm actually downloading the Firefox 2 beta that features a built in spell checker.

Hit shift then enter, at the same time.

djDaemon, I've had the same problem. I'll try skifan's advice.

Here goes.
Yes! That does it! Boy will this make starting poetry threads so much easier!
Woohoo!

Awesome.
As you can see,
it works for me as well.

Still strange though. Thanks skifan! :)