Recently I have come across an issue in Papervision that pops up if you are using smoothing. The issue only occurs when a smoothed material is viewed at an extreme angle where it is only a couple of pixels wide on the screen. This can cause Flash to take a major performance hit, or even lock up at times. luckily there is a simple and easy fix. If you set smoothing to true, be sure that you also set tiling to true, and this wont be an issue.