Don't look at the price of Steem Dollars to calculate your payout.
This is normal. 1 Steem Dollar (SBD) should always be worth 1 real american dollar (fiat). Or to be more precise: It should always be worth 1 american dollar worth of steem. So, if you get 0.5 steem for 1 dollar, you should also get 0.5 steem for 1 SBD.
But that's the theroy. In reality SBD is worth more than 2 dollars right now, but that is another thing caused by trading.
But that is also the reason why SBD was up yesterday. When Bitcoin drops in value, this means SBD should go up in value (relative to bitcoin, not in dollar). SBD value should not be affected by the drop of the steem price though.
So...Remember how I said your payout is always calculated in Steem/Steem Power and not in SBD/Dollars? This is why the dollar price can change.
If you make a post and it gets 12 upvotes and those upvotes give you 2,60$, this actually means you are getting Steem/Steem Power in the value of 2,60$. Let's assume the value of steem was 2,60 dollars at this time. This means, your post is worth 1 Steem. Now if the price of steem drops in the next days, let's say to 1.50$, and you didn't get any new votes, this means you should now see a price of about 1.50$ on your post. Actually a little bit more, because the calculation is based on an average of the days (not sure about that yet).
I know, a little complicated ;) That's why I want to make a post about this as soon as I have all the infos I need. Many people have questions about this.
If anyone has more infos, feel free to share. Also tell me if I got something wrong ;)
Thanks for the detailed reply, really appreiate the time you have taken to reply to me.. It kind of makes sense to me now. I think someone from steemit need to explain the process maybe in the FAQ section ..
No problem :)
I will make sure to resteem your post when you post it up..