@jankusanagi@datamost.com I noticed the same server deficiency for GNU Social also.
This is an effect of the "guaranteed message delivery" from #AndStatus side and "duplication problem ignorance" from the Server side.
I hope pump.io will fix this some day @alex@pump.strugee.net ?!
The long story about duplicated posts, caused by communication problems, is here: https://github.com/andstatus/andstatus/issues/83