404 error on form submit

Hi, I have a problem with chronoforms v4.0.5 on my joomla. When I submit my form I get 404 error.
I read through the forum and changed my field 'name' to 'name2', I turned SEF URL and cache on site, I changed template, but nothing helped.
I even updated joomla from 3.2.1 to 3.3.0 - although not sure if that was a good idea.
Here is a link to my page
http://ldsconf2014.tk/index.php?option=com_content&view=article&id=18
You will have to enter any value in third field to submit the page.

Here is this form testing page and it works
http://ldsconf2014.tk/index.php?option=com_chronoforms&tmpl=component&chronoform=Profile_form

Any ideas on why this happens?

Oh, one more thing - I also have chronoforms v.5 installed on my site. But I also tried to disable this extentions and run this form - didn't help either.

The interesting part is that it doesn't work only if I insert my form into an article
Luckily, there is no need for me to use an article, so I will go that way.
But still this is an interesting question why this won't work.

Hi Yury,

Do you have a field named "id" ?

regards,
Max