Has no one tried to upgrade the firmware yet? I'm having some issues with slower than expected internet connection, already contacted my ISP, just thought it might worth upgrade the firmware while waiting for them to check.

Did you extract the file first? Did you upgrade the firmware by cable connection?
If possible, try different web browsers and PCs.

OMG. I didn't think of that...

I've been using .zip file directly on some other routers, so didn't think that I should extract the .zip file first. Anyway, I extracted the .zip file and use the .bin file for uploading, the modem is running on the latest firmware now.

Thank you very much!