Please keep an eye on the CPU usage that Stereo Tool reports during a glitch (the display under CPU & Latency). If it jumps up at that point, something on your pc is blocking the processing.
Edit: Or your CPU jumps to a slower speed, that's also possible.
Thanks for the suggestion. I monitored and never noticed a change in the CPU usage when a glitch happened. To further test, I ran a CPU benchmark to see if audio would glitch when the CPU was under heavy load but no glitches were noted. I also did the same with the hard drive with no effect.