Did you erase Nvram between each upgrade? For my new RT-n66u that they stocked me with (I RMA'ed my old RT n66u after they said some part of the internal circuit had 'shorted'), I made sure that everytime I upload a new firmware I do the following:
- Erase Nvram with telnet.
- Upload new firmware (never use your wireless connection to upgrade firmware... it'll still work but the performance will be unstable so always use wired connection).
- Once you get into the new firmware setup page, erase NVRAM (and I always reset my WPS as well, to make sure everything is a clean wipe on the wireless settings).
- Re-upload settings.
I've also found that by upgrading any firmware wirelessly it causes my download speed to become unstable (once I uploaded .260 stock firmware wirelessly and my max DL was only 600KB/sec as to normally 3-4MB/sec). And the problem consistantly occured no matter what firmware I upgraded to or how many times I erased nvram; until I put the router into rescue mode & recover the whole router from scratch, then the DL speed returned to usual around 3-4MB/sec.
But again, the past experience from my old ASUS RT n66u router is that... not every same model router works the same! (especially when your own router is already not performing like it should in some areas). You can try some of my methods, but IMO you should just contact ASUS support; they're really nice people (from my RMA experience), so maybe call their customer support line for help. Good luck!
- Kuby
