Hmmm, if you're using the percentage system, I don't see why you need to grab the device width and calculate it based off the image pixel size. Best part of the percentage system is you don't have to deal with any of that!
If you're play map is sized 100% width, than this is all you need to get the tiles to be the correct size...
SetSpriteSize( map_current.spr_block , 10 , -1 )
Of if you have different size maps...
size = 100 / number_tiles_width
SetSpriteSize( map_current.spr_block , size , -1 )
So if you only have 5 tiles going across, size is = to 20. So tiles are created with a width = 20% screen width, so 5 tiles will fit perfectly side-by-side in the x direction on any device or screen resolution without any other fiddling.
Cool thing about the percentage system is you don't have to factor in anything else, like multiple screen sizes or resolutions. You might be over thinking it, or trying to compensate for that, but you don't have to.
Let me know if that makes sense.
Side note..after typing the code snippet I immediately hit crtl+shift+s...lol
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