Don't know what the issue could be, but I would try:
~/Library/App support/Reaper/User plugins/
MacBook Pro 15" i5 mid 2010, 8GB, OSX 10.9.2 Mavericks, latest 32 and 64-bit Reaper
MOTU Traveler mk3 (+2*ADA8000), Focusrite Saffire Pro 24 DSP
Focal Solo6 Be, Focal CMS 40, iPhone 5 iOS7, *Registered Reaperer*
Last edited by mrelwood; 03-09-2012 at 05:03 PM.