Globe Wimax

I'm frustrated now with the connection of my WIMAX plan 1mb of Globe. First because my plan is 1mb but it's always 500kbps I'm getting when I checked it to www.speedtest.net. But thats not the main frustration for the said ISP, it's o.k that I'm getting half of my plan, but the one that I'm pissed off is that when I'm playing online games specifically HoN (Heroes of Newerth) it's kinda laggy I cant play a decent game since last night. And I noticed that my ISP is change in xxx.xxx.xx.98 or 100, I've noticed that if the last quartet is 200+ it is ok for games no lag at all. I'm searching the net for some fix to change this.

O.k I have notice that when I turned my modem off, It'll change my ips's ip, but I'm turning that modem so many times now and I'm getting two results it's either 98 or 100. I already reset the modem but theres no way to get the 200+ quartet of the ip. Is it that the Globe blocked that set of IP's? I'm hoping thats not the problem...