The four examples given at comment #17 above seem to be OK now but I'll leave this topic open (not resolved) pending advice from Diigo team.
Me too! Thanks!
28 May 10
This bug seems to have reappeared. Looking at POST and PUT in the API, my sense again is that PUT (or PUT-like) operations are bugged.
not a word from Diigo support
> This bug is ancient It was reported a few months ago but to the best of my knowledge, it has not been present throughout the entire period between then and now.
I'll give it some time, hoping for a fix of this bug, because - as you say - the features of Diigo are really useful.