Oddb411: EDIT: Today my computer doesn't seem to be able to run well when CPU cycles are set to 60,000; the sound and music get a little choppy and explosions in-flight cause large FPS drops. But setting it to "Max 60%" instead appears to do the same thing for fixing the bug, while running much smoother, even during an explosion. Strange.
StyleWan: In my test, "Max 60%" does NOT fix the bug. Make sure to check whether the platform begins to fire at you at a distance of 1.3 km.
Strange, because the platform behaves the same for me whether I set the CPU to "Max 60%" or "60000" cycles. The platform starts firing at 1.3 km, but not necessarily at me; the other TIE Bombers in the flight group are usually targeted first. I typically notice a target lock about 0.90 km out. I also checked the GOG 1994 DOS version with the default CPU setting at max, and it behaves the same way.
I got my X-Wing DOS CD in the mail on Monday and while the 1998 Windows version has some nice upgrades, it loses a lot of the charm from the DOS predecessors. I think X-Wing is more personal preference when it comes to the DOS vs. Windows versions, and my preference definitely leans towards the former. The voiced mission briefings and the option for "easier" missions may not be as significant as TIE Fighter's enhancements, but the 1994 CD-ROM is still a welcome improvement over the original floppy disk release. It would be nice for GOG to include both of those in the near future.
EDIT: I changed the CPU setting to "Max 50%" and while the platform still begins firing around 1.3 km, it seems to target me earlier, closer to 1.0-1.1 km. Its firing rate is also increased so it's closer to the YouTube video of 60000 cycles. Lowering the max cycles to 50% doesn't seem to have any perceptible decrease in performance compared to 60%, so I'm sticking with that for now.