Installing 6.x-1.x-dev over an old installation throws an error

Situation: A Drupal 5 installation is updated to 6, and the Restricted Search module is re-enabled. It runs through its install procedure and throws an error "Table installation for the Search Block module was unsuccessful....[etc]".

I believe this is an erroneous error caused by search_block_install() when attempting to install the tables over an existing installation. drupal_install_schema() does not return 'success' because the tables already exists, so the module reports the error despite there being no actual problem.

I've written a simple patch which runs hook_update_6000() - though it doesn't do anything, and doesn't give a warning. Running Restricted Search with the old tables after this seems to work okay.