transparency problem with png's.

[Whywhywhy]

Hello. Today I have a new problem with removing the background in an image. The alpha channel comes up white after "select>invert>delete" just like it's not a PNG file even though it is. My workflow is thus- File>New>Ok>Layer>Transparency>Add Alpha channel>Click the eyeball in the layers box to pull up alpha(it does come up in the alpha pattern)>click the chain icon to lock. File>Open as Layers>>open PNG file>Paths Tool>Make sure it's in Design>make path>at the end, hit enter to complete the chain>Select>invert>delete. This is where the background should be "alpha" and it's not. It has always worked until today. Yes, I have had the "it must be PNG" lesson already. Any ideas? Do I need to re-load GIMP?  Thanks for your time.  J