Same issue. Works fine for a while then crawls to a halt. Then pages don't load at all. I end up rebooting via Advance settings a few times a day. I have 5 PCs on the network with Comcast cable. Reset the beacon interval and fragmentation interval per the first psot. Seems to have helped for now but we will see in a few hours. Already ran through complete reset up of the network and configuration of the Valet 10
Just wanted to say... Thank you sooo much rpi86. This solved ALL my problems. Not only great speed now, but previously Firefox was the only browser that wouldn't stall on websites. Now everything is running great. Thanks for this tip!
I've had the M10 for a week now and it is terrible. It's amazinf that when I run on online speed test, the speeds are awesome, but it takes forever (and sometimes never) to load a web page. I've tried upgrading the firmware, rebooting and anything else I've read in this thread. This is my first and last cisco. I find it amazing that with all the complaints of slow internet connection, I see no response from Cisco.
I have determined the problem is caused by the Cisco Connect software. Hold the reset button in on the router for 10 seconds until the power light starts flashing. Use a computer with a wired Ethernet connection. Use your web browser to connect to the router at http://192.168.1.1. Login is admin and password is admin. Manually configure your router. You will loose the added functionality of the Cisco Connect software but at least you'll be able to surf the web.
I replaced the router before I figured this out. It's a shame such a nice product would have a major bug in the software. I have two wireless laptops, two wired computers and a Windows Home Server on my network. Hopefully Cisco can reproduce this problem and fix it.
Before change = 13 mbps. After change= 20 mbps 
