What in the world might this be?

I am using the autocomplete plugin succesfully in a Rails 2.3.2
application. However, when I run in firebug, when it first renders, I
get the following error, below. Can anyone tell me what on earth might
be the cause (and cure?) of this? Thanks, RVince

element is null
anonymous(Object name=element)prototyp...249466790 (line 3588)
anonymous()prototyp...249466790 (line 3723)
anonymous(function(), "channel[channelnote_note]", 1, function())
prototyp...249466790 (line 3708)
anonymous()prototyp...249466790 (line 248)
klass()prototyp...249466790 (line 51)
uplog?update=UpLogBody()uplog?up...UpLogBody (line 175)
[Break on this error] var method = element.tagName.toLowerCase();
\nprototyp...249466790 (line 3588)