API: event.acknowledge empty eventids

[Mojah]

Hi,

I'm using the event.acknowledge API call, as described here: http://www.zabbix.com/documentation/...nt/acknowledge

Here's what I send, and what I get in return:

Action: event.acknowledge
Request: 
'{"auth":"c279e07729f74dc4c80e3ae6364246ff","method":"event.acknowledge","id":1,"params":{"eventids":["2101"],"message":"fhjjrtyery"},"jsonrpc":"2.0"}'

Response: 
'{"jsonrpc":"2.0","result":{"eventids":[]},"id":1}'

The "eventids" only lists 1 id (since I'm only going to ack them one by one), and it's a valid eventID. If I go to my zabbix server (webUI), and I want to acknowledge the link from there, the URL also lists the eventid 2101

acknow.php?eventid=2101

Does anyone see a problem with my API requests, am I missing certain (undocumented?) parameters? Any clue as to what to check as a possible cause of it?

[Mojah]

This seems to have been a problem in Zabbix 1.8.3, when tried on a 1.8.5 host it works just fine.

So if anyone else is having troubles: upgrade your zabbix server! :-)