Considering how incredibly sloppy your bug report is, I'm surprised I know what you're talking about.

1) What on earth is the "second set" supposed to mean? The second set of missions? There's only one mission pack. If you mean the second
act of the
main FreeSpace campaign, you should say so. Even better would be to give the file name of the mission, sm2-06, or the title of the mission, Shell Game.
2) There are no cruisers in that mission. There is a
destroyer in that mission, which is what you should have said. Again, it would have been better to give the name of the ship: the Eva.
3) This is the wrong forum. The FreeSpace Conversion forum is down in the hosted section. That's where you need to put bug reports and questions such as these. In the General FreeSpace forum, it is more than likely that a) your question would get lost in the shuffle, or b) nobody who sees the thread will know the answer. The people who are ready to solve FSPort problems will be in the FSPort forum, not necessarily this forum.
In summary, your bug report is inaccurate, incomplete, vague, terse, and in the wrong place.
Please try to make better bug reports in the future. It's frustrating for us because we have no idea what you're talking about, and it's frustrating for you because your problem doesn't get solved.
At least you used proper spelling and grammar, so you get brownie points for that.

Now that all that is out of the way: your problem is caused by a bug in FreeSpace Open that has since been fixed. Download a more recent build, such as Release Candidate 3.