Crack the code!

[Nia M]

Terrible thread title, I know, but I think it gets the message across
Seeing as I loved the Code-Breaking Competition so much, I thought I'd come up with my own code for you to break. There are no prizes for winning this one, but I'll give whoever solves it first +1 rep.

lt yg lt zh ow em px
00 00 00 px hp 00 xf
ow hp hp dl px tb mu
zh sa ck 00 we dl px
xf tb px yg we 00 ck
px nv yg zh 00 ck px
00 sa 00 em mu px ow
tb 00 ow 00 fn xf .

Clues:
differentiation = owtbqyqypxckpxygemtbltemtbzhyg
00 = a space
. = .
Down the stairs, then along the corridor

(Please don't post the unsolved riddle, but only what you think is the solution )