Unifi Problem, Disconnect

Hi guy i needed some help with my unifi..so it goes like this,

While i playing game it get disconnect all of a sudden this is the model that i use :
1.DIR-615 using this firmware [http://forum.lowyat.net/topic/2552840] thx to shuyina
2.[http://everyoneconnects.net/world/wp-content/uploads/2012/02/modem.jpg] dunno the model but given picture
3.8-Port Switch Prolink psw810

Ok this is some of the step that i have done
1.i try using without the 8-port switch and plug my plug into DIR-615 but the result is the same
2.i have changed my firmware into 7.15 thx to shuyina coz previous forum they say is my firmware upgrade should be ok but it not
3.i have try report at game forum [http://forum.hon.flying spaghetti monster.com/showthread.php?28493-Chat-Server-keep-disconnecting] but all the step i have done except the part about calling tm ppl to come check at my house

And some of the online game wont dc such as dota 2 and maplestory
the game that keep disconnect me is League of Legend and Heroes of Newerth

so this is what i need u guy help
1.any solution can u guy give me to solve this problem?
2.if i needed to call the tm guy come let say he change moderm and update something how to prove that the internet wont lost from connection...