I've been using the Kong Builds lately and have been happy with them. Just make sure to use the right build number. Currently, I use Kong Build R18050 here:
http://www.desipro.de/ddwrt/K26/r18050/
There still seems to be some kind of memory leak or wireless driver issue with the new drivers but I'll wait and see it improves.
If I have to resort to the DDWRT official builds, I resort to the R14929 by BrainSlayer, also known as BS builds found here:
ftp://dd-wrt.com/others/eko/BrainSlayer-V24-preSP2/2010/08-12-10-r14929/broadcom_K26/
I am getting a little worn over the whole wireless issue and trying to find the maximum settings so that everyone can work at peak performance. Here's what I currently use:
1.NG Mixed Mode
2.Channel Wide 40MHz
3.Extension Channel Upper
4.Channel 6 if possible & Channel 8 if not possible.
5.17 TX Power
6.WPA Personal Security Mode (not WPA2)