seems to be reproducible in 2.2 branch r49611.
works fine in 2.4 and trunk
So if i want it fixed in my zabbix. I have to upgrade zabbix frontend?
Using this how to? https://www.zabbix.com/documentation/2.4/manual/installation/upgrade
Alexander - do you fixed this right now in this version 2.4 or it was already done?
please use zabbix community support channels via forums, irc and other means - see https://www.zabbix.org/wiki/Getting_help for more detail
Fixed in r49682, branch svn://svn.zabbix.com/branches/dev/ZBX-8860 (copy of branches/2.2).
I upgraded zabbix to 2.2.6 from debian wheezy repo and it's fixed 
Thanks
Are You sure it is fixed? Because if it is, then it is really strange, as the bug causing this is present in 2.2.6 (but IS fixed in 2.4).
Sorry i wrote this too fast.
I don't know why, but it works for only one time
I marked two items, added flexible intervals -> update and it works so i wrote about this.
Later I marked 7 items, added flexible intervals -> update and it works fine only for 4 of them, for the last 3 items this didn't work.
Now i tried added flexible intervals again only for two items or even 19, but again don't works.
Behavior You describe is weird.
But anyway - fix for this will go into 2.2.7, which should be available soon.
Fixed and merged to 2.2.7rc1 in r49751.