Ralink 539b (RT2800PCI) very slow internet

Hi
I have bough an HP G6 laptop with these network cards:

           driver: r8169 ver: 2.3LK-NAPI port: 3000 bus-ID: 08:00.0
           IF: eth0 state: down mac: 38:ea:a7:e1:1b:ec
           Card-2: Ralink Device 539b driver: rt2800pci ver: 2.3.0 bus-ID: 07:00.0
           IF: wlan0 state: up speed: N/A duplex: N/A mac: a4:17:31:58:40:95

The problem is that: on this laptop the wired network is working very well but browsing andn downloading speed on wireless netword is very slow.
I did some research and found that my wifi card "Ralink 539b (RT2800PCI) had some speed and connectivity issues in the past. Almost all the solutions recommend to upgrade the kernel to 3.2 or higher. So, this problem should be there in my kernel which is 3.8.
Can anyone help me to solve this problem?
PS: I am using Linux Mint 15. The WIFI router is 10 feet from my laptop and there is no blockage b/w the laptop and wifi.
Presently, wifi inidicator is showing signal strength of 51%
Also, on the same laptop on windows 7, wifi is working very well.
Regards

all i can suggest is to disable encryption on router and that if that solves problem, however you can always get lucky with other distribution like ubuntu or some distro that uses other network manager.

Some people are talking about disabling power saving. Does that help? How can I disable it?

sudo iw wlan0 power_save off

this maybe?