Off the top of my head I'm going to say you have a version prior to 1.3. Check your about box or get info window to verify this. I know I have 1.3 and I believe the buttons are silver on the bottom of the screen instead of gold. I'll have to check sometime--I don't have the CD in my drive right now. Next I play I'll confirm this.

I'm not sure what the new copies are these days, but I'd imagine they are 1.3 or newer, possibly a modified version of 1.3 without the 25th Anniversary stuff. If anyone out there bought a copy of Oregon Trail II in a jewel case let me know.