I have dir-615 rev. b of course, ok so, i have updated my firmware to the latest version, but somehow internet, especially desktop which is directly wired, became very slow. it is not always slow but it is not stable. Also, when the desktop is on, other PCs which connected wireless, became slow as well but when it's off, others are fine. I have searched through this forum and found out that QoS might cause the problem so i turned it off but it did not help. After that, I finally decided to downgrade to 2.24 since there were no slow speed problem with this firmware, but still not stable. Should I downgrade all the way down to 2.21? is there any other users that had same problem but solved?
thanks
PS I am not really sure whether it happens after the upgrade or not, but it did work fine. I had this for about a year.