Calling $.blockUI when the GrowlUI message has not yet faded-out, I can cause the $('#blockWarning') element to be removed from the dom altogether. It's a timing issue, the call to $.blockUI needs to be made just as the $.growlUI element is in the process of fading out, any sooner, or after the element has faded out, and the jquery element is not removed from the dom.
I'm guessing that this has something to do with GrowlUI reusing the underlying BlockUI code and causing the second BlockUI call to loose the captured position in the dom which the JQuery element should be returned to.
I am using JQuery v1.4.2 and BlockUI v2.33.
I can reproduce the deletion behaviour 100% of the time, as long as the GrowlUI div is fading out when I call $.blockUI(..
Ta,
Derek