form- option request editor bug

I suppose it's bug... Choosing 'form' tab makes some request data disappear. Not for all webservices, i found out only for this type(there's nothing special about it e.g. it's not the longest). On the other hand i didn't check others. It was in  3.0 pro and it is as well in 3.0.1 pro... It happens also if the 'form' tab is set as default request editor. Check attachments. 1st shows how it supposed to be, 2nd shows applying 'form', and 3rd shows how it looks like in xml after.