Question : Access record navigation is not working in my custom application

I have an access DB that has been split into a back end (with tables) and a front end (user interface forms).  I believe i initially tested it and everything worked for a while, but i cant say that with 100% certainty since i may have missed testing the specific item that isn't working at the moment.  There are basically 2 things that aren't working and i think they are related because both deal with record navigation.

First, the front end user interface has navigation buttons that were added with the "add button" wizard in access.  I thought that, at the time i completed this, i tested all of these buttons to make sure that they worked.  I basically have a mulit-tabbed input form that is tied to about 4 or 5 database tables.  You should be able to navigate through the records with the navigation buttons and see each record populate in the input form.  When i hit the forward nav button, the form is populated with "new" in the id field (which seems ok).  when i hit the back button, it says "Record not available".  I verified by looking at the table that there are many records in the table that i should be able to navigate through.

As a second, and i think related problem, there is a combo box where you can pick a particular salesman from the dropdown.  In a listbox below, all sales opportunities from that particular salesman are displayed.  When you click on one of the opportunities shown in the listbox, the form should populate with that particular opportunity.  Again, i THINK that this must have worked when i tested it, but it doesnt now.  the listbox populates fine with all the opportunities of the salesman, however, when you click on one of the opportunities, the form does not populate.

As info,
Here is my rowsource from the combobox.  It has two columns, first one is bound with width set to zero:

SELECT [Employees Extended].ID, [Employees Extended].[Employee Name]
FROM [Employees Extended]
ORDER BY [Employees Extended].[Employee Name];

In the combo box "on change" event i have this:

Private Sub filterNAME_Change()
'for filtering Opp Id's by salesman
Me.salesmanfilterlist.Requery
End Sub

salemanfilerlist is the unbound listbox where the results are displayed and where you should be able to click on the one you want.  For this listbox, here is the rowsource:

SELECT keystoneopportunities.[ID], keystoneopportunities.[Opportunity_Title], keystoneopportunities.[Salesman]
FROM keystoneopportunities
WHERE (((keystoneopportunities.salesman)=[forms]![OpportunityInput].[filterNAME]));

and here is the "on click" event for the listbox"

Private Sub salesmanfilterlist_Click()
'for filtering Opp Id's by salesman
Me.Recordset.FindFirst "ID=" & Me.salesmanfilterlist
End Sub

for the custom navigation buttons, i simply used the button wizard, selected record navigation buttons.  It places a macro for each button.

Answer : Access record navigation is not working in my custom application

i solved this by eliminating the relationship to the "attachments" table, and then adding attachment fields into the main database table "keystoneopportunities".  Not sure what the problem was with the relationship, but this works correctly now.