I have upgraded from Ubuntu 13.04 to Ubuntu 13.10 and now my WiFi doesn't work. It takes a lot of time to connect but when connected, connection is quickly lost again. In Ubuntu 13.04 worked fine.

Here are some outputs:

lspci | grep Wireless

01:00.0 Network controller: Ralink corp. RT3290 Wireless 802.11n 1T/1R PCIe

sudo rfkill list

0: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no

lsmod | grep rt2800

rt2800pci              18966  0 
rt2800lib              95449  1 rt2800pci
rt2x00pci              13287  1 rt2800pci
rt2x00mmio             13661  1 rt2800pci
rt2x00lib              56053  4 rt2x00pci,rt2800lib,rt2800pci,rt2x00mmio
mac80211              634661  3 rt2x00lib,rt2x00pci,rt2800lib
eeprom_93cx6           13344  1 rt2800pci
crc_ccitt              12707  1 rt2800lib

dmesg | grep rt2800

[   19.959959] rt2800pci 0000:01:00.0: irq 46 for MSI/MSI-X

modinfo rt2800pci | grep 3290

alias:          pci:v00001814d00003290sv*sd*bc*sc*i*