Well I uninstalled everything that I had installed and a few other things. I never entered any data into the Z. It went back to a whole 50k...lol. I reflashed with henteges oz 3.5.3 now I have 1.4 mb. I installed something, uninstalled it, soft rebooted and whammo 700k left . There does appear to be some problem with freeing back the space on /dev/root and it happens with both stock 0Z and henteges roms.
Try checking the free space then install something. Uninstall whatever you just installed then check the free space again. You'll see what I mean. Something is still left behind but where...what?