Setup group are decimals allowed

I am trying to add a setup group with decimals.

I had tested this in our test system a year or so back and it worked OK and I created test setup groups with decimals in them.

eg ROD4.5

But now when trying to create our real data it does not let me.

We have since upgraded our ECC system to `

EHP6 FOR SAP ERP 6.0

Release 606

So possibly it is a change in the support pack.

The message I get is

Special characters are not allowed for Select group

Message no. CP250

Has anyone else created setup groups with decimals? Is there some config that I am missing? Or would this be

a change in the support pack?

Thanks

John