while creating a new block that summarize all "module"_print_overview() functions from all "modules"
i found out that the oublog_print_overview() in your module - oublog does not work correctly due to a tiny
sql "missing space char" error:

currently:
[line 694] $sql .= '(l.course = '.$course->id.'AND l.time > '.$course->lastaccess.') OR ';

the fix: (space before the AND)
[line 694] $sql .= '(l.course = '.$course->id.' AND l.time > '.$course->lastaccess.') OR ';

btw, love your module !!!