This only happens when the user is choosing the root folder each time they choose a voice.
To fix this:

1) Launch your host application
2) Launch your Sampletank
3) hit the root key
4) direct your browser to the folder called Sampletank Instruments and NOT the catagories INSIDE the folder
5) Hit Choose
6) now all the different catagories (Bass, Drums, guitar and so on) should show up in the middle of the red area
7) the arrow at the top helps you navigate thru the catagories.