I think I might discovered the problem, the new type of CF-connector I used with some boards has pin order somehow different ... And I might have tested the board using the IDE connector instead of the CF slot. (More at the end of this post...)
The "LD33" regulator shouldn't get hot.
Do the CF cards still work with the slingshot+a2091+scsiidecf combination, or are they burned? I hope not.
What kind of IDE-CF adapter do you have at the end of the ribbon cable? Unlike I wrote in previous post, +5v should be supplied separately, because no +5v supply is fed through the 40-pin ribbon cable.
The unsuitable CF-connector I've soldered on some latest boards have pins in swapped order in pairs, such that signals that should go to top row of pins go to the lower row, and vice-versa.