This is almost a game-breaker for me, really. It ruins the entire aesthetic value of the game when I can't go up to the Cursed Abbey and have the music sound different than it did in Aleroth, despite the fact that I know that it changes on the CD version. It also doesn't play the harpy-thing in the Market. It's breaking the whole aesthetic for me, and takes away from DD's epic, immersive feel.
Oddly, though, some themes still play. The Catacombs worked, as did the Abbey's basement... it's just not playing alternate overworld themes, for some reason. Anyone else hearing this problem?

If you have a dual core system you might try this as a possible fix.. I does fix the static problems on some dual core systems and eliminates the need to do the affinity change manually.
If it helps, post back the results as others may have a similar problem. . . =)

I have a quad core system, and tried using the proposed fix. It did not work, and I am still left with no luck in getting the score for the marketplace. I'll check in a minute to see if the Abbey gets its tune readjusted, but I doubt it.

My system is a quad core as well. I assume yours is an Intel too?
Edit: Using the Teleporters, I get the same music at all sites. Not sure what music you are expecting but this seems to be the standard on the last two patched releases. . . =)

No, my computer is AMD based. The music thing may be an issue that Larian didn't realize. Perhaps a slip in the source. I'll provide a link to the songs that are -supposed- to be there.
http://divinedivinity.info/music.php
The 'harpy' thing I was talking about is the 'Celtic Harp' song, while the song that's supposed to play in the forests between towns is the 'Forest' theme. I didn't catch the 'Cursed Abbey' theme anywhere, but it's separate from the base track you listen to already.
I'd love to figure out what's going on with the music, though.. it throws me out of my nostalgia when I -know- something's missing.

I'm quite sure I've heard the harp one somewhere, I think it was in Verdistis.
However, I've also noticed there are some tracks not present in the game, for example Track 16 from the downloadable soundtrack, but I didn't know why, as I've never played with the CD version.

Like Drlstvaan, I have also heard music similar to your description. This makes me think it is either a hardware or install problem. I only have a couple of suggestions as I have not heard of this problem before.
Sometimes, music files can be in different formats and your system may be playing only one of the formats for different reasons. If you are hearing music . . . in all locations . . . I tend to think it is simply a change they have made in the game since your CD version was released. If you hear nothing in a location then I would consider it to be a problem.
If you are running Vista / Win 7. . .
When installing, on Vista / Win 7, you need to right click the setup.exe and click "Run as administrator". Both OS's tend to block some disk writes if the setup is not run as an admin. If you just double clicked the setup.exe . . . you may not have a full install and would need to backup your saves and reinstall using the right click / admin method. Make sure you manually delete any folders left over after the uninstall. After reinstalling, right click the game shortcut, click Properties, click the Compatibility tab and check "Run this program as an administrator". If you are running Win 7, uncheck "Run this program in compatibility mode for:" After trying the game you would go back and try the modes if it does not run correctly.
You might try the AMD Dual Core Optimizer as another possible fix. It worked wonders for Painkiller on my laptop.
Check your sound card drivers for the latest update. MS and hardware manufacturers have added lots of DRM to the OSs and cards trying to stop users from easily copying audio and video output. This may be as simple as updating to a newer driver or turning off hardware acceleration for your sound card. Good luck . . . =)

I don't know... spiritual_arrow seems to imply that the music should switch in certain overground areas, which I also don't usually experience (the Ducal Inn being an exception). Like I said, I've never heard Track 16, which, according to the author's webpage, is "Drunk with Dwarven Myrth", thus I think it *should* play in the Dwarven Bread Inn (or some other similar area).

I agree, seems to be a change in the game music. I get nothing in the Dwarven Bread Inn but the sound of birds . . . same as outside??
I'm trying to eliminate all the install / hardware problems first but . . . seems there is a definite change in the game music. Might have been done in a previous patch for some reason or in a recent patch for a bug fix?? I never noticed it before . . .=)
If it is a program change . . . not much chance of a fix now. It doesn't affect the game play for me since I never knew it anyway . . =)
Edit: Certain music could be quest or progress activated as well.

The tracks that I'm noticing were not quest-oriented, but instead locale oriented. I played the game for roughly 40 hours on the CD-version, so I know they're not locale oriented. It is beginning to make me go nuts to find out that the music that made me so absorbed in this game world is just -not- there..

Did anyone figure out the resolution to this problem?

Not that I'm aware of