SOOO SIMPLE! Thanks!

Hi,
I'm trying to install the round corner plugin but it just wont work.
I've installed LibFredo6 4.6 in the plugins folder, then Round Corner 2.3
I even tried unistalling everything (including sketchup and all of its folders) and installing again, and nothing...
Then I tried deleting the date that came on the name of the folders available for download at the begining of this post and again, nothing...
I'm using Mac OS X 10.6.8 and Sketchup 8 (free version).
Can someone please help me.
Thanx