If someone is holding just one of the ds strobes, then it is not 00, but still...

If someone is holding just one of the ds strobes, then it is not 00, but still not 11.  Check for not being 11.  Also check as and dtack checks to be similar.

src/vme_data_bus.vhd

@@ -700,9 +700,9 @@ begin
           -- AS, DS or DTACK before we consider leaving
           -- TIMEOUT state.
 
-          if (vme_ds_n_i = "00" or
-              vme_as_n_i = '0' or
-              vme_dtack_n_i = '0') then
+          if (vme_ds_n_i    /= "11" or
+              vme_as_n_i    /= '1'  or
+              vme_dtack_n_i /= '1') then
             -- Someone is still holding a strobe.
             n_wait <= c_N_TIMEOUT_WAIT;
           elsif (n_wait = 0) then