just follow the instructions in their website and check your micro sd card isnt a fake/corrupt.
I ran the h2test - no issues with the sd card at all that I can find. I will go back and try the process again. The card is a 8g Kingston class 4 hc.
I drag and drop the roms into diskwriter - it writes them .. then I close it. eject the card, then place in cart. Hold blue button in, insert, wait, no lights, pop out, in - 3 lights, pop out, pop in .. game shows up .. *then* try pressing button to switch and flashing blue (not crazy fast).
Where should I be when I press the blue button? in the game? at the menu? in system with the prior game closed? does it even matter?
All games I have tried have been EEPROM games -- I dont know what that is/means.
You shouldn't need to hold down the button at all. Just put the cart in your console. If a Rom is already loaded, you may not get blue light at all when inserting. I just switch the game from the main 3ds dashboard by pressing the blue button once. When selecting a new game, the light will stay solid for a few seconds the flash briefly then go off while the new game loads into the dashboard. Be sure all the roms you are loading are for the same region as your console.
So where are saves stored when using roms on Sky 3DS? With the blue button version I can write as many roms to the micro sd as I want. But if I play like the 11th game, will that overwrite the 1st game's save?

16gb sd card - sd formatter, copied 2 roms over. Inserted cart, rapid blue light flicker. then out . nothing showed. popout and in, ridge racer (u) starts up.
No blue lights.
Hot damn .. press once, steady blue then pilot wings (u) starts up!
Press once, steady blue then ridge racer shows up again!
So to conclude Kingston 8Gb 4 hc didnt work (no errors found).. and kingston 16gb did work.
Note too .. i was using the internal laptop sd slot w sd adapter with the 8gb (didnt work) whereas the 16gb I did thru the usb port and a usb2.0 adapter.
Going to add a few more roms to double confirm.
[Confirmed] Like others it boiled down to an incompatible sd card. I retried the steps with the 8gb card and what worked with the 16gb card didnt work with the original 8gb. I will return the card to the vendor as it sounds like others had similar problems.

You can update any game you have via the eshop no problemsCan i install the update for Pokemon Alpha Sapphire without a problem?
Better, can i install any update for a game i have on Sky3DS ? or do i just push A to skip the update screen and start the game?

You can update any game you have via the eshop no problems