JQuery BlockUI.js Plugin Memory Leak issue

Question

While investigating a memory leak in IE11, using the developer tools I found some DOM Detach elements.
After doing further investigation, inside I found Document fragment sections where some HTML nodes were still retaining memory and not being garbage collected.

Here's code from the BlockUI plugin

var s = "Some Div tags" var lyr2 = $(s);

$() is adding in document fragment
I am using jquery 1.7.2 version, 

Please find line numbers . https://github.com/malsup/blockui/blob/master/jquery.blockUI.js#L293-L326

assistance appreciated