Glad I came across this thread before I posted my problem!! ;)
I was having similar problems like "namviet": On my laptop (WinXP) I was able to surf using LAN, but no luck using WLAN!! >:( In addition, through WLAN I was not able to ping my gateway (192.168.1.1) and yet I was able to access the web interface and make any changes that I needed to make without any problems. ??? I even had my NIC "disabled" when I'd have the wireless NIC "enabled", and vice-versa (to avoid any possible conflict).
I know it's weird and doesn't make sense. And yes, I did have the firewall rule setup for the WLAN.
Thanks to "Perry" and the pic he included, I realized where my mistake was…..in the firewall rule for WLAN I had the source as "LAN Subnet" (fyi, I had also tried "any", which obviously didn't work) and not "WLAN Subnet". This was the difference maker for me. Such a mistake had me going in circles.
Thanks again and hope this helps whoever is running into the same problem.