Thank you for posting the screenshot. That select multiple that you circled is not supposed to be there, except when debugMode is on. But I just reproduced that here too, and you are right, it looks like there's a problem there with IE6. Specifically, the problem appears when the 'sortable' option is set to true.
I did test this before, so not sure how I missed it ... IE is a tricky beast. But it could be something specific to my example file, because I setup another test case, and the issue did not appear. I'll do more testing here and find what the deal is, but I would assume it's a bug in asmSelect since the code is still drying (beta). I'll have an update soon. Thanks, Ryan