Error getting UDF value

Hi,

I'm trying to get the values from some standard fields and some UDFs on the Sales Order form

Everything works fine for the standard fields but I get an error on the UDFs

Here's my code

'This bit works fine

Set oForm = SBO_Application.Forms.Item(FormUID)

Set oItem = oForm.Items.Item("8")

Set oEditText = oItem.Specific

strDocNum = oEditText.String

'This bit doesn't work

Set oForm = SBO_Application.Forms.GetFormByTypeAndCount(-139, 1)

Set oItem = oForm.Items("U_CrPrj")

'The next line causes a type mismatch error????

Set oEditText = oItem.Specific

strDocNum = oEditText.String

Anyone out there have any idea where I'm goin wrong?

Thanks