Exchange 2010 with IOS 6.0.1 & Distribution Groups

Hi All,

Have a problem with our IOS 6.0.1 devices and all our distribution groups.

On a IOS device such as a Ipad or iphone when you open a new email and search for a distribution group, where the name should be it states "No Name" but lists the email address.

I have a screen shot here:

http://bohemiangrove.co.uk/Issue1.jpg

I've also tried this on a IOS 5.1.1 but it doesnt seem to use the name:

http://bohemiangrove.co.uk/Issue2.jpg

Any one seen this before or have a idea for a solution?

Thanks