Excess Usage reported in upload

Hello,

I have been using bsnl broad band for the last 5-6 years. Modem I use is QuidwayWA1003A. I have formatted the system in the first week of march 2009. After formatting the usage has gone up exorbitantly. On analysis I notice that the change is in the upload. My upload used to be around 30 % of download, whereas now this has gone up to 140 %. But the nature and volume of work I do is almost the same as the previous days. Could somebody, who has experienced similar problems and resolved the problem, help me to resolve.