Just wanting to share my experience while searching for wifi USB dongles.
I also bough a WUSB100 for 29eur initially.
In the list of supported there is a remark “no revision” in bold. You must interpret this as “the revisions do not work”. It seems that the older versions of this dongle still had a linksys design, the new version V2 I had has a black cisco design. On the back of the stick it is marked WUSB100 V2. Do not buy this version as it doesn’t work.
I don’t think there is anything clealy indicated on the box.
This one will have to be sold second hand.
I ended up buying a D-link DWA 140 revision 1.31 and can confirm this revision works (on the list of supported devices it is like only the 1.30 works). On the box of these devices you can clearly see which version it is. In Europe it seems this version is available everywhere now.