The problem is in:
bibione-appartamenti.com
residencebibione.it
bibioneferienwohnung.de
jesolo-appartamenti.it
rimini-appartamenti.it
appartamenti-cortina.it
The previous websites have the new version of CF7 (3.4)and there is the bug with different browsers and themes.
I'm Italian but I use English Wordpress.
I have many others websites with old version of CF7 and I have no problem with tetx area; for example :
ferrobattuto.net
chirurgia-plasticaestetica.it
The server is the same for all websites.
I've thought about downgrade of CF7 plugin, but I don't find any files
Sorry for my English and thanks to your help.