wp-link-engine.2.0 user losing clicks (affiliate)

Hi

I am an affiliate marketer and I currently use a plugin called wp-link-engine.2.0 to mask my links. I have noticed a low click through rate from my wordpress pages to offers and when I started optimizing (using visual website optimizer) I noticed that about half of my clicks were disappearing before they got to the offer.

Has anyone else seen this? Is this the plugin, do I just need something else to mask my links?

Any info would be great, thanks for taking the time to read this.