var block = jQuery(".widgetBody", $(elementid));
var blockstatus = block.getStyle('display');
It seems like the problem is mixing the jQuery object, block, with the prototype function, getStyle(). The error is removed when I replace the second line with a call to a jQuery function instead:
var blockstatus = jQuery(block).css("display");
I guess it makes sense that combining jQuery and Prototype code is a bad idea. I was using Prototype to begin with then started using more and more jQuery, and never went back to clean out all the Prototype. Heck there's even Prototype in the line with the jQuery search! Anyways...laziness is costing me now.