The import box with the options in the resource manager is only skipped if the image file already contains transparency data - which means that you saved into a format that supports transparency, but didn't use or save transparency data.
Yea ok sigh, that's easier said then done, and been trying to do just that for hours now, with little-no success. Thanks anyway though..
Making something transparent is usually very easy in a good image program. Here is how it's done:
1) make a new picture with transparent background (preferably with the same pixel size of the image to be edited)
If your image program doesn't allow you to select whether the background of a new image is white or transparent upon creating the new image, then you can stop working with the program and start looking for a better one - because that means that the program itself doesn't support transparency, and nothing you do will ever create a transparent background when working with that specific program.
2) import the image to be edited as a new layer into the new image file
If the program doesn't support layers - see above
3) select eraser, make sure that the layer with the image is selected and erase all pixels that you want to be transparent
4) save as PNG
The two most important basic options of any medium or professional level image program are transparency and layers.
If your image program doesn't support those two functions, then scrap it - you will never be able to go beyond the most basic image editing with that program, and you'll only waste hours of working time if you try to make an image partially transparent with it.