Cubase 7.5 Crackling and Superior Drummer 2 Issues

Total newcomer to Cubase and home recording in general. I’m having two issues that are frustrating to no end. My first is that after Cubase 7.5 has been open for a few minutes everything develops a disgusting crackling noise. Audio tracks, the click, everything. Restarting the program stops the problem, but it always returns. Any advice? I also cannot get superior drummer 2 to show up in the VST instruments window or in Cubase in any form. I have it installed in the VST plugins folder, but it simply doesn’t show up anywhere. I can load it outside of Cubase just fine with Toon track Solo, I just can’t get it to show up in Cubase. Any help is greatly appreciated.

Hi WS, your crackling is prob just due to your samples/buffer size. Have you tried to get latency down too far for your system? Device setup, your audio interface, control panel and adjust it there, try 128 see if that helps?
Are you sure your VST drum is mapped to the correct VX2 plug in path?

Thanks so much for the help! A couple more questions:
How do I create a new MIDI item for a virtual instrument track? And, how do I monitor through my interface? It’s showing up as an input source but not as a an option for output. Thank you again!