Yes, this is happening to me as well using K4.1 with VEP 5436.
The strange part is, in the (64 bit) instance where it happens, it loads the first 5 channels of K4.1 no problem. It's only the 6th and final channel that the plugin will not load. The Channel shows up, with it's name and all, but no plugin. If I close that instance and load a saved version, it loads up just fine.. weird.
btw, this is happening on a Mac Pro (slave machine) with Snow leopard.