Okay, as the search is not working and there is no immediate match visible on first page, I'm making a new thread for this problem.
The problem shortly: Launcher 5.3 is not working. Or actually it did, for a short period of time. Then, without a warning, it ceased working altogether. Luckily, The Babylon Project comes with Launcher 5.2 so I'm able to play the game through it.
My system is the following:
Windows XP Home SP2 Finnish Edition
AMD Athlon 64bit 3200+
1024 MB DDR-SDRAM
NVidia GeForce 6600 256 MB
The build I most often (and currently) use is fs_open_367_p4. I still use MediaVP 3.6.7 release.
What makes this thing a bit weird is that the launchers behaved just the same way some time ago. Then I had to make a complete reformatting due to other things, and after making a clean new install of Freespace 2, downloading MediaVP's and builds and using Launcher 5.3 for some times, BANG, it doesn't work any more. When I try, my comp just sits there, thinks a moment and then up pops a Windows-generated error message.
I reported Microsoft about the problem, as if it would help.

Anyway, this problem is not of utmost importance (for me) as I can use Launcher 5.2 in stead of the newer one. I just felt that maybe someone wanted to know if there was a problem with something released. It would really suck had I not downloaded TBP with a working, older launcher version - had I only DLed the official 3.6.7 pack, I might not be able to set up flags, choose graphics and stuff easily and so on. I would have to write the flags onto command line - or rather write a freespace2.bat file with the appropriate flags, and run it anytime I'd like to play FS_Open...
I don't know if I should report this bug or whatever it is into Mantis; I don't have any further information about this matter. I don't know where the launcher logs error messages (does it even do that?) so I couldn't file in a very accurate bug report. Has anyone else been having trouble with launchers? Have you been able to circumvent/fix the problem otherwise than using another launcher?