Just in case you don't know, the keyboard needs to be unplugged when you adjust the dip switches.
Maybe you can try unplugging, switch the dip switch, and then plug back in to see if it works?

Anyway just to let you know, I'm using my 87U with my MBP dual booting Yosmite and Win 8.1.
No problems with the Winkey registering as CMD in Yosemite, but it seems that the Num Lock won't work in OSX.
This keyboard is not 100% compatible with OSX. The only Topre keyboard I know that works well in OSX is the HHKB.
