excel is forgetting the values of formulas???

Hi!

I got an issue with my file of excel :/

I got a big file. One sheet where all the calculus are done (with some personal functions), and the others sheets link to this worksheet to display the values we want.

my issue is that each time i make a change in my file, the values that are calculated by one of my formulas just become "#values", even if i change a cell which isn't linked to the cells with my formula :/

what can be the problem? is excel releasing memory?? :/ because i have to perform a forced calculation (by pressing CTRL + ALT + F9) on the right sheet! each time i do a modification :/

thank's in advance

are you sure you have the option for calculation on Automatic?

yes calculatio nis set to automatic!

for the function, here it is :

Function LIVRAISONS(date_debut As Range, lignes As Range, type_cam As Range, dates_livr As Range) As Double

Dim tabl() As String
Dim i As Integer
Dim rng As Range
Dim result As Double

result = 0
tabl = Split(lignes, "/")
Set rng = Range(tabl(0))

If UBound(tabl) >= 1 Then
    For i = 1 To UBound(tabl)
        Set rng = Application.Union(rng, Range(tabl(i)))
    Next i
End If

For Each c In Intersect(rng, type_cam)
If Not (c.Value = "" Or c.Value = 0) Then
    For Each cell In Intersect(Rows(c.Row), dates_livr)
        If Not (cell.Value = "" Or cell.Value = 0) = True And date_debut <= cell.Value And date_debut + 6 >= cell.Value Then
            result = result + c.Value
        End If
    Next cell
End If
Next c
LIVRAISONS = result
End Function

date_debut contains a date
lignes contains a string like that :

173:173,196:196,209:209,212:212,214:214/237:237,250:250,253:253,255:255,278:278,291:291,294:294,296:296

type_cam is a range of cells in column (an entire column) cotainning integers
dates_livr is a range of cells (multiple rows and columns) containing dates

if you have any question, go for it, i know my function is dirty coded :/ and in french so it doesn't help to find the problem for you