Skim PDF Reader and Note-taker for OS X

Start a new AppleScript in AppleScript Editor:

tell application "Skim"
save document 1
end tell

Run script.

After a long time, receive message:
error "Skim got an error: AppleEvent timed out." number -1712

(the same thing happens when I try to control Skim from Ruby, the following two commands both stall, and worked fine previously:
skimdoc = app('Skim').documents[0]
skimdoc.save(skimdoc, {:as => "Notes as Text", :in => fname})
)

I am on OS 10.8.2, using Skim 10.4 (74). I heard about this bug from my friend, who had the same problem after he upgraded. (I use automatic export of Skim notes to a wiki as part of an academic workflow system: http://reganmian.net/wiki/researchr:start).