I noticed that in cvs slime the entire function signature (when typing a function/macro into a lisp-mode buffer) doesn't always get shown anymore; it seems to cut off after the first line.
For example, the signature for MAKE-ARRAY cuts off after "(element-type t)" in cvs slime (cmucl18e). I checked with slime-1.0alpha, and it works as expected there.
Cheers,
Iain