Earlier today Torley Linden contacted me to let me know that SLBuzz had stopped processing postcards sent from within Second Life.
Turns out that the issue was that the format of the embedded meta data had changed which the parser couldn't cope with. The new meta data is better as it also includes the region coordinates, not just the local coordinates. I modified the parser, and it's all working again, the backlog has been processed and nothing was lost. Currently, some of the postcards come in with old and some with new meta data, as there may be a rolling restart going on, but both formats are handled properly.
Keep the snapshots coming!