When trying to add a step to a web scenario zabbix fails the validation for the name.

If name field is left empty it says just:
Warning. Incorrect value for [name]

If anything is typed to name field it says:

• preg_match() [<a href='function.preg-match'>function.preg-match</a>]: Compilation failed: range out of order in character class at offset 16[/usr/share/zabbix/include/validate.inc.php(254) : eval()'d code:1]
• Warning. Incorrect value for [name]