Setup A List Of Names That Is Populated From A Userform

I've setup a list of names that is populated from a userform, this works OK. I have then tried to use a combobox (on a separate form) to use these names as its values, I first used the rowsource property but this only returned the first name in the list and after searching for the last few hours and trying different methods it's still not working.

Here's what I have;

To populate the list;

Dim irow As Long
Dim ws As Worksheet
Set ws = Worksheets("Clients")
'find first row in database
irow = ws.Cells(Rows.Count, 1).End(xlUp).Offset(1, 0).Row
With ws
.Range("A" & irow) = txtNewClient.Value

I have also tried the userform_initialize, with no joy either,