Actually I think I just experienced those stability problems.
I've had the DI-604 for a few days. No problems but I would have liked the extra security of an SPI firewall. I buy the SMC Barricade today at CompUSA. Just a list of problems I've had, some minor, some not.
1. The "EZ-Click" CD doesn't seem to connect to the router. I open an IE window, input the admin IP and it connects fine.
2. Tough time getting an IP from the ISP/Cable Modem even after resetting it for 5 minutes(it usually resets after only 30 seconds). The DI-604 picked up an IP pretty quickly. Eventually the Barricade gets one seemingly out of the blue.
3. Can't seem to update firmware. Router reports a firmware of 1.00 (with a July 3, 2003 date). Newest firmware from smc website is 1.23. I download firmware, unzip, and attempt to update. Router says, "Incorrect Firmware" or something to that effect. I try it a few more times on different occasions. It never works. Strangely, the Log file says, "job sent to printer" "job completed", every time I do this.
4. After surfing and generally testing the router for about 2-3 hours, all connection just stops. No websites, nothing. I can't even get to the admin page. I have to unplug the router for about a minute to get it to work again. Ironically, this occured when I had just pressed "post" after typing up a response to GhettoFob in this very thread. I had to retype everything because all my browser windows gave me a 404 error at the same time.
5. 30 minutes later, #3 happens again. I unplug for a minute and the net is back on.
6. Only 10 minutes after the last disconnect, the admin page completely disappears. The net still works fine but when I try to access the admin page, I get a white screen. I reset the router and it's back.
The bad thing is that I bought this from CompUSA. They are absolute Nazis about returns even though a product is defective. I'm going to have a tough time returning this without getting charged the stupid 15% restocking fee.