Hi! after course publish and start with Firefox, all course work good, but all dynamic object (lists with button "next") do not work properly - system write message:"CallMethod: 001_blocklist ShowItem undefined" and do not load object!

what its mean? and what can I do to correct this problem?

I have simple problem!
Please anyone help us with ideas!

If it works on IE but not firefox then it a specific call to one of the MS proprietry functions.
Sometimes it's just a glitch in the way the XML is written by the software.

Upside down!
On IE8 work properly, but on Mozilla 4 work wrongly and with errors...[:confused:]