intermittent connection with my dlink load balancing router

hi,

i have been experiencing this problem since yesterday, i have 5 computers connected to a switch hub and connected to a dlink load balancing router (di-lb604), it has often occurred that everytime we would be playing over LAN we would experience slow down with our game and when i would ping the router it would give several "request timed out" rather than the "1ms".

Also, there are times when i would go to the internet it would slow down and when i ping the router, it would give the same response of "request timed out" and subsequently, when i ping my isp's DNS, it would give a "request timed out" response.

from what end would the fault can be attributed? can you pls give me instructions on how to diagnose the problem and the possible solution

Hoping for your immediate help.