Latency when mixing in Track View with Browser window open to Project Audio Folder

Setup:
Large project (93 tracks, which include stereo and mono clips and soft synths),
Browser is opened to Media>Project Audio Folder [Folder has 900+ file names in it]
 
Behavior:
When I start or stop playback, there is large amount of latency (I get the mouse pointer's "wait" icon) until playback/ stop responds.  For playback, it takes a moment for the project to play, but then the mouse's "wait" icon comes up for a second or so; the same for stopping: the transport takes a moment, stops, then "wait" for a few seconds. 
This happens regardless of my latency settings (I tried various settings from 256 to 1024 buffer size)
 
There are currently about 900 clips in the folder (due to mixing and foleying a film...yes, all done primarily using SONAR), and this doesn't seem to happen when folders with fewer clips are showing.
This happens when the Browser is on Media>Project Audio Folder with a large amount of clips in them, and the latency occurs regardless of whether the Browser is open or closed. As soon as I change the Browser folder to, say, the PlugIns screen or if I switch to Mixer View, there is no problem.
 
Basically, this is an annoyance, but if you're seeing lag in the transport while in Track View, the problem may be the Browser looking at lots of clips.