Low SNR issue now solved

I have been facing low SNR(about 4 to 15) and disconnection from past few months and upon various complaints problem was unsolved. LDN customer service was quite satisfactory but the problem was at Ptcl's end. I came to know about a director at PTCL who was my father's friend, and contacted him about the line problem. He was kind enough and tried himself best to get my my problem solved but according him he was not getting enough support from the LDN guy there(at exchange) to check port or line. So I called LDN helpline again to register complaint and an idea came into my mind. I asked the CSR that I m thinking about 'upgrading' my 1mbps pkg to 2mbps. As my SNR are quite low, will my line support 2mbps speed or not? The CSR at once told me that:

'I am setting your line parameters as that of 2mbps. If your connection works well in these parameters without disconnection then you can upgrade to 2mbps. I am setting these parameters for 24HOURS so that you can test your connection. Your speed will remain same as that of 1mbps but your line parameters(In other words port speed) will be set as that of 2mbps. Kindly restart your modem.'

After that he gave me the complaint number and i ended call. When i restarted my modem i saw the port speed which was doubled to 2074/543 from 1050/283. And to my 'surprize' my SNR were quite satisfactory between 20 to 25 in other words my problem was solved. 3 hours later i received a call from LDN lahore office and the guy asked me about the line problem and about the complaint which i had made. I told him that my problem is solved since my port speed is doubled and asked him that it will be good enough if my port speed remains doubled but the guy said that if its ok at 2mbps then technically it should be gud on 1mbps port speed too. And now a week has passed my DSL line parameters are still set at 2mbps andnow i am having NO problem with my DSL. Hope I dont face any problem now because i have suffered a lot in past few months.

My question is: If SNR is low at 1MBPS parameters how can it be better in 2MBPS? According to my knowledge,if i am not wrong, SNR falls with the increase of port speed. In this case it is increasing.

Beats me man.... :|