I just wrote an answer that your key combination didn't worked for me and what exactly I did, but now I see that in your comment was an
Key part of this combination which didn't converted to an icon, so that I overlooked it.But anyway is it correctly what I did or do I have to wait for uninstalling in the ControlX menu?
What I did:
I uninstalled nBoot by pressing
in the ControlX menu, firstly it said 'Fixing SPI count', I pressed it a second time, then it said 'Uninstalling nBoot' I guess, since it didn't did anything I pressed 
to reset.After this my boot graphics were gone and it booted with a black and white loading screen.
Because it didn't worked for me, since I overlooked the
Key I used the way you suggested on top.I overwrote the two boot2 images with boot1.5 which are a much smaller, then I decreases the extended partition size with nsPartMagic and then flashed boot2 again in order to 'push the two small images over the boarder'.
