Rules administration menu broken - Fatal error: Unsupported operand types in modules/system/system.module on line 626

I've attempted to install this new version of Rules however I've discovered something strange after I install the module.

When accessing the menu link Administration > Rules I get a blank page except for the php error: Fatal error: Unsupported operand types in xxxxx/modules/system/system.module on line 627

When debugging this system.module line 626 shows

$item += db_fetch_array(db_query("SELECT mlid, menu_name FROM {menu_links} ml WHERE ml.router_path = '%s' AND module = 'system'", $item['path'])); 

The error seems to be caused by db_fetch_array returning false. $item['path'] has the value of admin/rules. I constructed the query myself and ran it, the query returned no rows.

I ran a generic query based on the one above and found the following information:
Query: SELECT mlid, plid, menu_name, link_path, router_path, link_title FROM menu_links ml WHERE ml.router_path like 'admin/rules%' AND module = 'system'
Query Result:

"mlid","plid","menu_name","link_path","router_path","link_title"
600,229,"navigation","admin/rules/autocomplete","admin/rules/autocomplete",""
601,229,"navigation","admin/rules/ie","admin/rules/ie","Import / Export"
606,229,"navigation","admin/rules/rules/%","admin/rules/rules/%",""
609,0,"navigation","admin/rules/rules/%/add","admin/rules/rules/%/add","Add"
610,0,"navigation","admin/rules/rules/%/clone","admin/rules/rules/%/clone","Clone rule"
612,0,"navigation","admin/rules/rules/%/delete","admin/rules/rules/%/delete","Delete"
615,0,"navigation","admin/rules/rules/%/delete/%","admin/rules/rules/%/delete/%","Delete"
616,0,"navigation","admin/rules/rules/%/edit/%","admin/rules/rules/%/edit/%","Edit"
614,0,"navigation","admin/rules/rules/%/revert","admin/rules/rules/%/revert","Revert"
602,229,"navigation","admin/rules/rule_sets","admin/rules/rule_sets","Rule sets"
608,602,"navigation","admin/rules/rule_sets/%","admin/rules/rule_sets/%",""
611,0,"navigation","admin/rules/rule_sets/%/delete","admin/rules/rule_sets/%/delete","Delete"
613,0,"navigation","admin/rules/rule_sets/%/revert","admin/rules/rule_sets/%/revert","Revert"
607,602,"navigation","admin/rules/rule_sets/js","admin/rules/rule_sets/js",""
603,229,"navigation","admin/rules/settings","admin/rules/settings","Settings"
604,229,"navigation","admin/rules/trigger","admin/rules/trigger","Triggered rules"

From the rows above I tried the URI admin/rules/settings and was presented with the rules admin settings page.