I was on wp 3.4.1 and all was fine.
Upgraded to wp 3.4.2 and now several plugins are not seeing their private style.css files including this and Responsive Slider.
If I copy all of the contents of the css file that is in the plugin folder and add it to my site css file then all is OK.
The buttons are losing the float:left on the div so are stacking vertically rather than across the row.
My site is still on my local server so I can't send you a link. I have rolled back to wp 3.4.1, thank heavens for Backup Buddy ;-)
I will also post the same message on the Responsive Slider Support page.