Argh! - solved it - if you disable spanning tree (have to use the web, not the command line interface since that wants to remove the BVI interface), on all vlans then the bridge forwards the BPDU's! This is actually great as we now have Rapid Spanning Tree Protocol running transparently across the bridges. In case your interested we have a Free Space Optics link in parallel with a pair of 1410's. The, now working RSTP, provides a very fast fail over in the event of a failure in our Free Space Optics (LightPointe Strata) link. Note that we use both links all the time with one vlan cost'ed to go over the FSO link, and the other costed to go over the radio link.
