--- Operating System, Graphics card ---

Linux64 and win32

--- Blender version with error, and version that worked ---

Trunk and 2.65a

--- Short description of error ---

The Factor: and Border: arrows on the sliders seems not to work. I think it is because of the very low value for the step of 0.0000001 in ./source/blender/makesrna/intern/rna_modifier.c

Together with my old settings (always imported) in startup.blend the LMB-Hold-slide method also don't work (seems there is somewhere a 0.01 factor, so you need to slide waaaaay long for any tiny change). Maybe above is the same problem but I did not like to klick 100 times...

--- Steps for others to reproduce the error (preferably based on attached .blend file) ---

Add an laplacian smooth modifier and LMB on the arrows of Factor: and Border: