sem fio cai depois de usá-lo

Question

Recentemente, instalei o Linux Mint 10 Julia. Tudo funcionou desde o início (até mesmo o dongle externo wifi), mas eu descobri que a conexão wi-fi se perde depois de algum tempo. Para resolvê-lo, tenho que desabilitar a rede e reativá-la.

Alguém sabe qual poderia ser o problema? Mais detalhes podem ser encontrados abaixo:

iwconfig wlan0
wlan0     IEEE 802.11bgn  ESSID:"myessid"  
          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:22:3F:91:15:89   
          Bit Rate=11 Mb/s   Tx-Power=11 dBm   
          Retry  long limit:7   RTS thr=512 B   Fragment thr=512 B   
          Power Management:on
          Link Quality=70/70  Signal level=52 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

iwlist wlan0 scan
wlan0     Scan completed :
          Cell 01 - Address: 00:22:3F:91:15:89
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=70/70  Signal level=51 dBm  
                    Encryption key:on
                    ESSID:"myessid"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=00000000027bf580
                    Extra: Last beacon: 6484ms ago
                    IE: Unknown: 00087461636B776C616E
                    IE: Unknown: 010882848B960C121824
                    IE: Unknown: 030101
                    IE: Unknown: 2A0100
                    IE: Unknown: 32043048606C
                    IE: Unknown: DD180050F2020101820003A4000027A4000042435E0062322F00
                    IE: Unknown: DD1E00904C334E101BFFFF000000000000000000000000000000000000000000
                    IE: Unknown: 2D1A4E101BFFFF000000000000000000000000000000000000000000
                    IE: Unknown: DD1A00904C3401051B00000000000000000000000000000000000000
                    IE: Unknown: 3D1601051B00000000000000000000000000000000000000
                    IE: Unknown: DD0900037F01010000FF7F
                    IE: Unknown: DD0A00037F04010000000000
                    IE: Unknown: DD820050F204104A000110104400010210570001001041000100103B00010310470010565AA94967C14C0EAA8FF349E6F593111021000D4E6574676561722C20496E632E10230007574E523230303010240007574E523230303010420004353637381054000800060050F204000110110007574E5232303030100800020084103C000103

O hardware wifi que estou usando é o seguinte:

lsusb
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 003: ID 07d1:3c09 D-Link System DWA-140 RangeBooster N Adapter(rev.B1) [Ralink RT2870]
Bus 001 Device 002: ID 1221:3234  
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

ATUALIZAÇÃO:

Ao tentar instalar manualmente o driver para o wifi, recebi esse erro ao compilar o driver:

make -C tools
make[1]: Entering directory '/home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/tools'
gcc -g bin2h.c -o bin2h
make[1]: Leaving directory '/home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/tools'
/home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/tools/bin2h
cp -f os/linux/Makefile.6 /home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/os/linux/Makefile
make -C /lib/modules/2.6.31-14-generic/build SUBDIRS=/home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/os/linux modules
make[1]: Entering directory '/usr/src/linux-headers-2.6.31-14-generic'
  CC [M]  /home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/os/linux/../../common/crypt_md5.o
In file included from /home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/include/rt_config.h:92,
                 from /home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/os/linux/../../common/crypt_md5.c:28:
/home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/include/mlme.h:1185: error: ‘MAX_LEN_OF_MLME_QUEUE’ undeclared here (not in a function)
make[2]: *** [/home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/os/linux/../../common/crypt_md5.o] Error 1
make[1]: *** [_module_/home/jean-pierre/Bureaublad/2010_0709_RT2870_Linux_STA_v2.4.0.1/os/linux] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-2.6.31-14-generic'
make: *** [LINUX] Error 2

Isso pode ser porque eu não consegui atualizar meu compilador? Enquanto estou conectado à internet (posso acessar a internet através do navegador), o terminal sempre responde com um erro 404 não encontrado ao tentar atualizar o apt-get.