I have noticed this with eboostr 3, and now while testing v4, it is happening again.
Every time (100% of the time) I burn a DVD, which is often, eboostr starts building its cache. The problem is that the added data transfer and CPU usage from the cache building makes the burning speed of the dvd drop significantly (from 12x down to between 0x and 1x). I just assumed it was just coincidence, but then I started canceling the cache build right when it starts, and within 10 seconds it will start building the cache again, automatically.
This happens on both Windows XP SP3 and Windows 7.