Simple and to the point, there are a couple of reasons why these issues happen and it has solved the problem for me. Hopefully you will have the same benefit.
1. PC is too slow.
Solution: I've seen people post about the issue, and when they give specs they are no where NEAR meeting the requirements, which is pretty much a 2Ghz dual core. Anything below will probably give you issues all day.
2. Using a laptop? Overheating is the issue.
Solution: This was my main problem, my laptop was simply overheating every time it need the power to run a game or the Roxio capture software in this case. I clarified this by opening the capture software with the laptop on my bed, and saw the glitchiness start to happen. I took it off my bed for about 3 minutes and hey what do you know, no problems capturing whatsoever. The fans are at the bottom of my laptop, so when it's on a soft surface(like a bed) the heat has no where to go, and it gets trapped in the laptop, causing it to overheat. When it overheats, your clock speeds go down to the bare minimum to save you the trouble of damaging your laptop, and when the clock speeds of your CPU go down, you no longer meet the requirements of the capture software. Mine went down to 933mhz, which is WAY below the requirements. Most laptops are set to cool down if it reaches a certain temp, most of the time it's 90c. It should rarely reach temperature unless you're doing some kind of overclocking or benchmarking. To solve this, just make sure your fans are free of any dust, make sure your laptop is on a hard surface or better yet, use a lapdesk or laptop cooler. Those will fix your problems. If you're on a PC, make sure your fans are clear of any dust, and that it's in a well ventilated area. If you haven't replaced your thermal paste on the CPUs in ages, that could be causing your desktop to overheat as well.
I hope this fixes your guys' problems, as it has fixed mine.