Incorrect function definition for block_block_configure

block.module defines block_block_configure() function as:

function block_block_configure($delta = 0, $edit = array()) {

The second parameter is not necessary as the invocation of the hook only passes a single parameter.

// Module-specific block configurations.
if ($settings = module_invoke($module, 'block_configure', $delta)) {

Will roll a patch as time allows unless someone else beats me to it.