Yup linksys is a bunch of silly clowns LOL for a lack of a better word when it comes to opensource , also for the lifetime they support their own drivers / hardware is about 6months effectively then they well just don't care no more or there abouts. Likely would be the same for their opensource drivers as well.
Have you tried the supported by the developers type like openwrt , hyperwrt tomato or similar just google for "wrt linksys linux" as some of them covers more than just the actual routers.
Someone has mentioned that the drivers / firmware for the wrt types can be striped down to get the actual driver for the chipset of the linksys pci / usb / ?? cards chips and then used in linux via ?? modprobe or something similar.
Most of the linksys stuff uses generic chips as used by most wifi cards and could likely get past the driver isues with using another makers chips driver to get yours started if better supported.
Example the bcm43xx chips.
Have a looks at alternative drivers for the wifi think it is in the "hardware list" topic we tried to get working recently. Not sure how updated this list is below.
*Wifi network cards here is a list + how-to link*
Complete linux wifi card + driver list: http://linux-wless.passys.nl/query_alles.php
Alternative drivers for Wifi cards: http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/