I've just tried this demo on my REAL TOS 1.62 STE with 4MB and the demo runs fine.
Try removing the Simms and trying each 1Mb module one at a time, you could have a duff Simm.
Also try Pouet Net for a copy of the Antiques demo. This is where I obtained my copy which works fine. Failing that try Demozoo.
If the above fails then i'm not sure of the issue. Do the disks still work correctly if you format them and put another demo on there? Is it just the Antiques Demo you are having bomb issues with?