Linksys WRT300N Wireless-N Broadband Router and the “AP Isolation” option

If you have a Linksys WRT300N Wireless-N Broadband Router and wonder why Windows file sharing (SMB/CIFS/Samba) between different wireless clients doesn’t work, find out that you can’t even ping other WLAN clients, then you’ll probably need to disable the checkbox cryptically labelled “AP isolation” in the tab “Wireless -> Advanced Wireless Settings” of your access point.

Dear Linksys engineers:

1. Please don’t set a default that an estimated 95% of all buyers/users of the product will need to change.
2. If you set a default that most likely will need to be changed by almost any user, please don’t hide the according checkbox in a submenu labelled “Advanced Wireless Settings”, targeted at advanced users.
3. If you decide to hide a checkbox for a setting which most likely will need to be changed, please don’t label it misleadingly “AP isolation” whereas the setting should rather be called “wireless client isolation”.
4. Fine. So you decided to label the checkbox wrongly. Why be so cryptic about it then? Can’t you at least label it “Access point isolation” instead of just “AP isolation”? Do you believe the latter will make life easier for joe average or experts?
5. Last but not least: Why isn’t the “AP isolation” feature/setting mentioned at all in the pop-up help of the according tab?

Thanks.