Hi! I also had this experience (Cubase, not Reaper). I found some useful info from the FAQ and from RJHollins:
"From FAQ definition: "Q – RATE CNV This parameter sets the upper bound limit for the sample rate conversion action. It is expressed in milliseconds This parameter is used for optimizing the loading time on slow systems. A large reverb program requires a large amount of time to load: in this case the rate conversion procedure is skipped."
IF you are working @ a different samplerate then the library was built at ... you'll see something like 96k -> 44.1 . The KEY is to see if you have a blinking arrow there ... if so, then the library was not fully converted, so you need a larger RATECNV value.
I think mine is set to 9000. YEAH, it takes a little longer to load, no big deal."
Did as you say Enrique, but made no difference. I am running a quad xeon machine. Its actually a mac running windows 7 32-bit (dont ask why...) I am trying to work on older projects that were running fine before in my previous XP installation (same machine)