Something is weird there with the EL's at Fotolia. I sold an EL for 20 credits today and my share was only 5.6$.

I'm bronze. I didn't know I can change my price. Can you please be more specific how can I change that?

Log into your Fotolia account and select "My Files"

Then, below click on "Uploaded files". Now you see the list of all pending, accepted and rejected images.

You cannot make price changes to pending images. You have to wait until they are accepted.

On the right of each row of an accepted image click on "Edit data", which takes you to the image's details.

Here you can change the importance of keywords by moving them up and down AND you can change the base price for your image (only worth mentioning for higher level contributors, Emerald and up for non-exclusives) as well as your EL pricing.

As Bronze you are able to set all your EL prices to 50 credits max.

You can see this information here on the Fotolia web site, posted in their FAQ section:
http://www.fotolia.com/Info/Contributors#item_8

Hope this helps.

by the way, what else we need to do once a rank change? other than able to change the EL credits..what else contributors may not be awared?

I just learnt today the credit we earn is also affected by what currency the customers had paid..and i am not sure how much we really get after all.

I just learnt today the credit we earn is also affected by what currency the customers had paid..and i am not sure how much we really get after all.

Wrong, you get your fixed payout per credit used, independent of which currency was used to buy the credit and independent of what discount was awarded to the buyer.
Therefore you know exactly how much money you will get for a sale of a specific size, but you don't know at all what percentage of the real sales amount that is.