Noises while recording guitar with input monitoring?

I'm hearing noises while recording guitars using plugins and input monitoring. Specifically, Guitar Rig, Amplitube and Podfarm. The noises are not recorded. The track is fine, it's just really destracting. It's hard to describe. It's a little like a delay time being moved combined with a clipping sound. It's not a click or pop, just a weird anomaly. It sounds like the pitch changes for a second.
 
Softsynths work. No noises while recording using input monitoring. I'm inputting to the guitar input (8) of a Tascam FW 1884. It also happens while using an Aphex 207D directly into the spdif input of the Tascam. 
 
This also does not occur in 8.5.  Any ideas?  
 
I'm using X1 Expanded. Win7 64bit, 3.1 Ghz quadcore, 12gb ram, Tascam FW1884 with 2 FE-8's.