I've been having problems with Stampede freezing after a minute or two of play on my Intellivision II. I thought maybe I had a bad cartridge, so I bought another Stampede on eBay. It freezes, too, in the same way.
I dumped the cartridges, and got the same ROM image from both. It has md5sum e39a9065388384cf439dc1484013d993.
When I try playing the ROM image on jzIntv, it freezes too, in the same way.
Any idea what's going on here? I swear that Stampede worked when I was a kid!