Great, then I just misunderstood your changelog. This was just what I was proposing.
But, I know, I am a spoil sport, I still get "... with ID: [...] could not be found on site: [CURSE]", so it looks like there is some more to it.
Anyway, great Job, Rolf. I really love JWU!
As far as i can test myself to, its Curse who is taking along time responding sometimes, as the error im getting in the .log (As of 1.84), is Socket timeout.
You can try raising the timeout value in the config and see if that helps.
Or just find the addon on wowinterface / wowui, and then update it from there instead if curse keeps being slow.