I'm attempting to setup a very basic form, with a Single Line Text field. I need to apply a custom input mask filter (aaaaa9). When I enable any input mask filter the form doesn't apply the filter and allows submission of any value or no value at all. I have tried with both the standard input masks as well as my custom one. No other options for the text field are selected, such as required or password field. It may be worth noting that input masks applied to advanced fields such as phone number are working.
Server details are as follows:
PHP Version 5.3.15
MySQL Version 5.5.25
WordPress Version 3.4.2
Gravity Forms Version 1.6.11
Any advice as two what might be wrong?