Why is the content of existing blocks not editable? I have inherited the Administration of a Drupal 6 site with major funkiness going on. In this case I can't even figure out where to look.

There are a few dozen blocks configured and for the most part they are displaying what they are supposed to. However, a few of them are either blank or need tweaking. When I go to the block admin page, I am able to configure the blocks and bring up the Block specific settings tab, however the normal fields are all missing. Only Block Title shows up and that appears to be blank across the board.



Strangely enough, if I go to add a new block of my own, the form shows up correctly with all the fields.



What could cause these fields to not be displayed for existing blocks or where would I find the content of these blocks to be edited?
I suspect that the blocks that are doing this are made via hook_block and not with the block UI (ie, admin/build/block/add).  I just checked a Drupal 6 site that I did a while ago, and all of my custom blocks have this behavior.

The Configure link for each custom block should contain the module name that defined it, along with the delta.  For example the "Who's online" block has this for the configure link:


  admin/build/block/configure/user/3


It is defined in user.module and if you look at user_block you will see that the $delta for this is 3.