blockUI - focus() called and not returning?

blockUI - focus() called and not returning?

Hi, I seem to be experiencing an intermittent issue where unBlockUI() is never reached and the user is left with what they interpret as a "hang" or "freeze".

I am on blockUI 2.42, jQuery 1.8.2, and running against IE8. In IE8, I had the developer tools profiler running and received the following as the last execution prior to the currently unrepeatable incident:

Function Count URL Line Number
focus 1 https://.../jquery.blockUI.js 496

Here is Line 496 in blockUI.js:
  1. function focus(back) {
    if (!pageBlockEls)
    var e = pageBlockEls[back===true ? pageBlockEls.length-1 : 0];
    if (e)
While I'm unable to recreate this behavior, I am able to mimic the profiler results by simply right-clicking the browser window once and not exiting the right-click menu just after blockUI() is initially loaded. This reaches focus(), but never returns until the right-click menu is dismissed on the screen. Once dismissed, unBlockUI() is then able to be reached and executed.

With that being said, are there a list of known end-user actions or events (like right-click) that are known to cause blockUI to wait until said user action has completed?

Thanks in advance.