I never had any problems with the campaign.
I've just realised that this week is actually a bad time to ask as Miburo's on holiday at the moment so he probably won't be logging on to HLP as often.
Since I'm in a good mood I'll take a look at the mission myself
kahkarot : I'll look at You Can't Hide From Death now.
N'Grath : I'll need the mission name or filename.
EDIT : Okay. Took a look at both the R1 and R2 versions of You Can't Hide From Death.
The R1 version looks perfectly fine. The R2 version appears to be messed up something chronic though. As far as I could see (and admittedly I only had a quick look through the mission) I don't think there is a way for the Janus to jump out. The SEXP that would make the Janus jump out is in an event chained to one that ony happens after the Janus has left.
I'll have a chat with Miburo about this after he gets back

. In the meantime try renaming mission MW_5.fs2 (You'll find it in data\missions) to MW_5a.fs2. That way the version in the vp will be used instead. That one may work better (although I haven't tested it).