C#/MVC4 Application

I'm attempting to create an IP address input that will be validated. I'm using a MaskEditor as follows:

@Html.Infragistics().MaskEditorFor(m => m.DeviceIpAddress).InputMask("099.099.099.099").ValidatorOptions(o => o.AnimationShow(500).OnSubmit(true).OnBlur(true).OnChange(true).FormSubmit(true).RegExp(@"^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$").CustomErrorMessage("IP address not valid").Required(false)).Render()

The validation is not working as expected - even with a valid IP address (e.g. 192.168.100.100) it raises a validation error.

I know the RegEx "^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$" is valid as I've written a jQuery function to test it, which works as expected:

$("#btnValidateTest").click(function (e) {
var ipAddress = $("#DeviceIpAddress").igEditor("value").replace(/ /g, '');
var ipAddressRegex = /^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$/;

if (ipAddress.match(ipAddressRegex) == null) {
alert("ip address NOT valid");
}
else
{
alert("ip address valid");
}
});

I've also validated the RegEx on an online checker (http://www.freeformatter.com/regex-tester.html) and it works as expected.

To rule out the issue being with the MaskEditor I also tried using a TextEditor, but I see the same issue:

@Html.Infragistics().TextEditor("Test").ValidatorOptions(o => o.AnimationShow(500).OnSubmit(true).OnBlur(true).OnChange(true).FormSubmit(true).RegExp(@"^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$").CustomErrorMessage("IP address not valid").Required(false)).Render()

I'm using 2013.2 of the IgniteUI controls.

Regards,
Dave