problem with drillthrough and relationships (cardinality)

Hard to tell from what you provided but try one of these.  Dealing with multiple fact tables can get a bit tricky. 

1. Filter on Slot from your Bidge Table this will force the filter down into both tables. 
2. IF you need to filter on somethign else then you can set the relationship between the bridge Table (SlotIDs) and the SlotReport table Bidirectional. This will force the filter to flow back up and then down into the other table.
3. You can use a trick to force the filter context by writing a measure for the slotdetail data that explicitly references the SlotReport table by specifying the table name within a calcualte.  (see some screen shots below)