Not sure if this is what you need, but on the options screen (press ESC while in the game, or Options from the main menu) there is a drop down window in the bottom right-hand corner for screen shot format.

It's not you. That is simply the format that that particular site is using. You are saving the file in the form it is presented. Some people use jpg, some use bmp, some use gif. They are all graphic files, but are different formats. Most graphic programs will be able to open all of them anyway.

Yes thx that is what I can do now it's just wierd that for the last three years I always was offered to save as a jpg file.And I am always so scared of messin my computer I know I did not change any prefs or anything,but thx and I better stop or these guys are gonna holler at me,but I do love this game even now before the big patch

There is an option for how to save Elemental screenshots.  From the start screen, hit "Options," and then under the "Gameplay" tag, in the very most lower right of that window, you can choose your format for saving Elemental screenshots.  If it is not "jpg" then switch it to that.  If it IS jpg but you are still getting bit maps, then that would be a mystery. 

As for saving screen shots from your internet browser, I imagine there may be a similar setting though would be surprised if it didn't save the picture with the same format seen in your browser.

None of this info is in the manual, so the average user is going to be unaware of this without deep digging or spending a lot of time sifting through forum threads.