I don't see the Black Market update. Is that the same as apply sdcard:update.zip?
Do you have Root Explorer?
Is so, open it, go to sdcard, scroll down to Darkslide and open it.
Then open Add-Ons. There should be an update zip in there for black
market. Long press it and hit copy, back out to the sdcard with all the
folders and zips and paste it there. Then run Bootstrap and apply like any
other zip.
If it's not in there go here and DL>>>
http://www.mydroidworld.com/forums/droid-x-roms/6155-rom-darkslide-v4-2-a.html