When using a Postgres database and calling getRangeCond() from includes/Block.php it will fail with the following error message:
SQL ERROR: ERROR: operator does not exist: text <= integer LINE 1: ...(ipb_range_start LIKE '%' ) AND (ipb_range_start <= 0) AND ... ^ HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
The reason for this is that ipb_range_start as well as ipb_range_end are declared as TEXT and compared to $start and end respectively which are integers.