Thank you for your detailed post. Unfortunately, I'm actually the firmware update guy at HP, not the scan and wifi guy. You might try reposting with just the scan and wifi issue? Or repost and ask which set of drivers are used. I think if you right click on my computer->go to properties->device manager-> printers you can check out the drivers maybe, but I'm imagining you're proabbly aware of that. I admire your trouble shooting skills. I'll see if I can forward this to a wifi person at the office.
I know there is another update coming out for your printer in a month or four (no guarantees). I don't think the update is to address this issue, but you never know.
BUt ya, try reposting your issue to find out which drivers it's using?