html reports drill - zk session/client hangup after approx. 5 docs opened

we found a strange behaviour. when you run a html report and user try to drill by e.g. documento more then 5-7 records then client session hangup. also looks me some zk components stopping to work (e.g. we are pushing some data to client by "push service".)

user must reload and/or restart his client/browser.

remark: this is very annoying e.g. when user doing a controlling operation and wants to open documents - by - documents for tens or hundred docs. i must classify this is really not usable.

version. 3.0