"Upgraded" to the Advanced kernel yesterday. And am now unable to see my network in my N900 as well.

When set to B-only it works.
When set to G-only it works.
When set to any of the mixed variants it won't work.

I am using a TP-Link TL-WR1043ND with Firmware Version DD-WRT v24-sp2 (08/07/10) std - build 14896

Another network in my building is using DD-WRT as well. With broadcast SSID enabled and this one won't show up anymore as well.

Is it safe to assume this is a DD-WRT problem and should be fixed by them?

Edit:
After looking at dd-wrt forums and upgrading/changing to build 15962 Mixed mode works like a charm.