I added a new flexile color to an existing style. While the style was being imported the ACP showed "Rebuilding...". I decided to use my 2nd pc to browse my forums. Any page I tried to use came up blank (a completely white screen, no message) within 2 seconds. I thought it to be a momentary glitch. When the style was finished importing, my site resumed working normally. A few minutes later I upgraded my XenPorta add-on with the current update. While my ACP said "Rebuilding Caches...." my site seemed to go down again in the same manner described above. When the update process completed, my site began working normally again.