The tests, which are summarized in this product preview, showed that the draft 11n radio, when used in 2.4 GHz band, 20 MHz bandwidth mode, had an abnormally low 12-13 Mbps throughput vs. the 60+ Mbps usually seen in draft 11n products.
Netgear’s engineering team, working with Broadcom, which supplies the key chipsets used in the product, found that some WNDR3300 boards had higher coupling of electrical noise from the digital circuitry into the draft 802.11n receiver. This was seen as RF interference and caused an "interference mitigation" algorithm to be activated, which reduced throughput when the draft 802.11n radio was set to 2.4 GHz, 20 MHz bandwidth mode.
The fix is a simple adjustment to the level at which the interference mitigation algorithm is triggered and can be done in firmware. No hardware changes are necessary.
v.1.0.23 firmware has been posted for download on Netgear’s support site.