OC'ing OC rams does
not void warranty unless you burn them by extreme overvoltage.these rams are meant for overclocking and not a single stick would sell if they put such restrictions.
Afaik Gskill \ corsair \ ocz gives a replacement on rams gone bad while overclocking .i've got 2 OCZ and gskill sticks replaced thanks to my bro for ruining them

.and if u check gskill support forum you will find out what i mean..
and the right voltage for a 24/7 run for Gskill 2*2gbhz (4gb d9gmh) that i run were given by gskill technician only
Safe overclocking=No warranty issues ..applicable only to performance ram..
Gskill forum--google it
Corsair performance page-read the text--
*www.corsairmemory.com/testreports/report_list.aspx?partner_id=325852