THAT SAID, it's entirely possible that something has been borked up that isn't popping up in my own code. If you download ENMTools from the GitHub repository and notice it acting weird in some way, please don't hesitate to raise a GitHub issue about it.
Also, there's a nice new function called raster.cor.plot that does this:
Which is pretty darn cute if I do say so myself. It's visualizing the correlations between a set of predictor rasters.