I also got a Tekken 4 Version D. Pretty sure the D was written on the dongle with a marker. No locked characters for me!
Now, I just hope it doesn't take 10 weeks to unlock the old Tekken 5 stages in Tekken 5 Dark Resurrection.
If the other Tekken time-release unlockables are anything like in Tekken 3 and Tekken Tag Tournament, the game would just count the hours it's powered on and running (well, probably not including test mode). Stuff like actual gameplay time or credit counts didn't matter. Back when I was messing with MAME I didn't know how to unlock the other characters in Tekken 3 and Tag so I just left MAME running in the background on a laptop for weeks.
I guess there's nothing really stopping me from doing that right now with real hardware (except fan noise while sleeping, maybe)... but at some point I would like to play Tekken 5.1 again without getting another 256. Where are the hacked ISOs/dongles for T5DR??