After a long research I found that most probably there is a problem with madwifi drivers and motherboard interrupts....
check your /proc/interrupts to see if there is any conflict (wifi interface is using the same interrupt with anything else).
I changed the motherboard (even if it was a brand new one!!!) and now the problem has totally disappeared!!!
No errors in the logs, no crashes at all and my three wifi cards works absolutely fine!
After a long research I found that most probably there is a problem with madwifi drivers and motherboard interrupts....
check your /proc/interrupts to see if there is any conflict (wifi interface is using the same interrupt with anything else).
I changed the motherboard (even if it was a brand new one!!!) and now the problem has totally disappeared!!!
No errors in the logs, no crashes at all and my three wifi cards works absolutely fine!