Insert fx different results from applied fx issue

I have stumbled across a vexing issue that I have never encountered in the past. When applying Noise Reduction (NR) to an event the result is different (and worse) than when the NR is occurring realtime as an insert effect. Problem is I always tweak NR parameters with the effect as an insert (so that I can hear the results of my changes in realtime) then save my settings as a preset within the plugin and apply the effect to the event. Yet I’ve never had an issue with the applied effect sounding so different from the realtime effect.

I am using Isotope Denoiser 3, running Nuendo 6.06-32bit on a Windows 7 PC. I want to reemphasize that I have been doing NR on a bunch of dialogue tracks, and have always worked the exact same way when using processor intensive fx (i.e. tweak with insert, save settings, apply to event) without ever having had this issue. It is as if the applied track has a high-pass filter applied; it sounds phasey and awful. If anyone has had the same issue using this combination of software/plugin or can offer some insight as to what may be happening I would appreciate your input. Files below:

Original

Insert NR

Applied NR

Null of Insert & Applied NR

Thanks in advance for your help.