Since there is alot of issues regarding wireless ethernet cards, why not use an ethernet to wireless adapter?

Is there any downsides using these?
I've already bought two wireless cards that has given me hell...

Perhaps you are refering to a wireless bridge. Bridges are all hardware, that is, there are no drivers or anything installed on your computer, the bridge (if set up properly--with the cisco one's I've worked with this can be a pain) operates transparently to the computer.

Cost.

It is twice to three times as expensive as a pci card.

alose; that is wrong.
It might be a little bit more expensive, but since its transparent, it will be a good combination for linux, and hassle free...

Baddox, why should it be a problem?
Since it's not interferring with any software, and the config is trough a web-browser, should be better than alot of unsupported wireless cards...

Well I was configuring a Cisco Aironet 350 through a terminal with IOS. The hard part was getting both wireless bridges to connect 2 seperate wired LANs. I would imagine it would be better and easier just using one bridge to connect to an AP. I was doing this in my networking class, so we just used IOS which isn't even close to friendly.

As far as cost goes, it's not bad at all. A D-Link AirPlus XtremeG High-Speed 802.11g Wireless Bridge goes for about 80 bucks online. Definitely worth it I'd say, and I'm sure that D-Link would be way easier than the Cisco.