While browsing through a Lost Patrol fansite, I found a snippet of information which may be the explanation to my woes.
Hi!
I got real problems playing the game. Every time I get to the mountains and the map scrolls one page to the right, my men die away and put grenades in my bag and all that, so I lose the game. Before the scrolling everything is fine - no dead, no injured, morale around 85, health too.. what's happening? Would be nice if you mailed me some ideas. Oh, I get there around 12 o clock of day 2.
Seems like there are some players who encountered the exact same problem I did, yet the majority of people didn't. The reason for this is that there were actually two versions of the game in circulation - a pre-release version, and a final (working) version. The pre-release version appeared to contain several bugs, some of which may have been crippling enough to prevent completion of the game. The above-mentioned bug was one of them.
Whether there's a way around this, I don't know, but at least it's shed some light on the matter.