Nice to hear you found it useful. However the guide is currently once more slightly out of date (I hope for the last time ), the main change being that if we 're talking about a "list" block you have to inherit from block_list instead of block_base.
The block getting deleted when the two formats are in the applicable_formats array is a bug. Thanks for the report, I 'll take a look.
Jon
General developer forum
1.5 Block Updating
This discussion has been locked so you can no longer reply to it.