Strange download speed limit

Hi, I am having problem of slow download speed but i can't seems to find the reason it happened.

With the same laptop, bitcomet setting, and a lot of peer for download resources, I used to have 180 kbps download speed at my hometown( hometown internet speed is 2mb) but when i moved to my hostel this morning, the download rate reduced to around 40 kbps. (my hostel internet speed is 4mb, which suppose to give me 2 time faster speed than at my hometown)

I'm not a new bitcomet user and i do made configure the NAT setting of my modem to unblock my download port for both 2 area.
I do made speedtest to confirm the internet speed for both area.

I observed the pattern of my download rate, its like whenever the speed is trying to go beyond 40 kbps, it will fall down into 40kbps again. Its like something that holding it to stopping my download speed to go beyond 40 kbps.

I am absolutely sure that i do not set any upload/download limit on bitcomet setting nor task specific limit.

I wish someone can help me to diagnose the possible reason that made my download speed to be low.

Thanks

Bitcomet 1.36 64 bit running on window 7 home premium 64 bit
Internet connection ADSL, from Telekom Malaysia
Modem is innacomm W3400V6 for both hometown and hostel area
Tested and same things happened to other p2p software