Here is the code that I always use when I have an unbound form and am adding records to a table from the fields on the form.
Dim cnCurrent As ADODB.Connection
Dim rsTable As ADODB.Recordset
Set cnCurrent = CurrentProject.Connection
Set rsTable = New ADODB.Recordset
rsTable.Open "TableName", cnCurrent, , adLockOptimistic, adCmdTable
With rsTable
.AddNew
![TableField1] = FormField1.Value
![TableField2] = FormField2.Value
![TableField3] = FormField3.Value
.Update
End With
rsTable.Close
cnCurrent.Close
Set rsTable = Nothing
Set cnCurrent = Nothing