VBA Code To Return Multiple Found Range Objects

I read and used the Find_Range custom function provided by Aaron Blood. It's a great function, for which I have many uses, but, as I currently have it set up in conjunction with a userform, it doesn't work fully until I use it twice in a row. The first time it's used to return more than one row, it seems to stop short and only display a few of the appropriate rows. Not until it's used twice in a row does it display all the rows containing that product. What do I need to do to have it work fully each time?

I have a large worksheet from which I want to extract only the rows which contain a certain product, selected by a combobox, and paste the rows on another worksheet. I have a userform set up with an oversized listbox which displays the contents of the data worksheet. Below that I have a 'products' combobox, and a button to initiate the Find_Range. Another oversized listbox displays the results.

Here's the function contained in a module:

Function Find_Range(Find_Item As Variant, _
Search_Range As Range, _
Optional LookIn As XlFindLookIn = xlValues, _
Optional LookAt As XlLookAt = xlPart, _
Optional MatchCase As Boolean = False) As Range
Dim c As Range, FirstAddress As String
With Search_Range
Set c = . Find( _
What:=Find_Item, _
LookIn:=LookIn, _
LookAt:=LookAt, _
SearchOrder:=xlByRows, _
SearchDirection:=xlNext, _
MatchCase:=MatchCase, _
SearchFormat:=False) 'Delete this term for XL2000 and earlier
If Not c Is Nothing Then
Set Find_Range = c
FirstAddress = c.Address................................