It seems like there's been a slight change in the way this character looks on Skritter. The dots used to be symetric, but now they're almost parallel.

I'm just curious why this has happened

According to Wenlin, 火 (with dots "almost parallel") is the form of the character as a component. In the independent form of the character, the dots are rather perpendicular.
Here's Wenlin's explanation:

"At the side of a character, 火 is written [I can't paste the picture, but it shows the side form of 火, with dots "almost parallel"], as in 灯 dēng 'lamp' and 烟 yān 'smoke'."

Right. It also seems to be a personal stylistic choice if you look at how different fonts do it. George just standardized all these in the manner above because in our system, the dot used for the almost-parallel style can be written either down-left or down-right and still recognized, while the down-right dot cannot be written down-left.

I was a bit bothered by 火, without knowing exactly why. It's all right now. Thanks to both of you.

I always found it a huge pain to write in Skritter. Actually probably the single most difficult to thing to get Skritter to recognise, possibly because I was insisting on doing it wrong.

It seems to have been easier lately but maybe that's just me finally getting some skills :)