Old Logic + a new Mac = can't open old projects anymore. De/re-install?

Question

Hi everybody,
maybe someone can advise me with this problem:
I bought a new Mac recently, did install a fresh OSX 10.5 and then used migration assistant to transfer my old user account from my old Mac (10.4), incl. all files. It did take a night, but it worked - or so I thought. Actually all applications work as they should, except for Logic. I had to re-authorize a few plug-ins, but then all seemed to be cool. I can open a new project, record audio, midi, add plug-ins, all cool. But I ended up with 3 problems, which are really annoying:
1) EXS24 couldn't find most of the samples anymore. Most, not all. I have 4 internal HDs, one for the system, one for audio recordings, one for samples, one for "other stuff". 2 of these disks came from the old Mac, 2 new ones, content copied from old Mac. In the EXS prefs I set "search for samples" to "all volumes", but it still didn't work perfectly. Finally I bought EXSManager Pro and now it seems to work again. I didn't try ALL samples yet, but the +/- 20 EXS instruments I tried, did load all samples.
2) Space Designer doesn't load impulse responses for the presets anymore. They're there and at the right place. I can load SD and import an existing impulse file, no problem. But the presets don't find the required files anymore.
3) Now - and this is the worst one - I can't open old projects anymore. I just can't. It starts loading, I see the rainbow thing (don't know the right word), it turns black & white and that's it. You can watch this forever and nothing happens.
Regarding all 3 issues:
I don't get any error messages. Logic doesn't crash, I can't click 'apple-.' to stop loading/searching. It just doesn't open the file. I had a coffee, a pizza, I let it try for 2 hrs+, but neither did it load a SD preset or an old song file. All I can do is manually quit Logic.
But when I open Logic with the CTRL-button down and click "no" to core audio I can open all songs. Of course I can not hear a tone then, but it's all there. Opening a song takes 3 secs then. I tried to safe a song then with a different name, re-started Logic with core audio but same result. It get's "stuck".
Of course I checked user permissions and all the usual trouble shooting clicks, but still Logic has a mind of it's own. I installed a 2nd user with admin rights, though still the same, plus all the 3rd party plug-ins refusing to work.
Now I was thinking, should I de-install Logic and re-install from the original CDs maybe. And if so, is there anything special I have to take care of? Like manually removing any prefs or cache files?
Or completely re-install the whole Mac? (pleeease no....)...
If anybody has any idea, it'd be highly appreciated.
Thank you in advance and for the energy to read my little novel here,
cheers,
Joern

Answer 1

Ok, either my question was too long or nobody seems to have an answer. Sad, either way
Here's something I found out in the meantime, maybe this is interesting for somebody or maybe - problem's not totally solved - enough info for any of you to give me further advice.
When I start Logic Core Audio driver de-activated, I can open old songs. Then I save them in a new folder with all audio files and a new name. And I remove all EXS24 instruments as well as the Space Designer. I quit Logic, re-open with Core Audio activated and I can open the song.
Problem no.1: EXS24 instruments don't find the appropriate samples, but EXSMananger Pro did help me with this. Same problem with Space Designer, which doesn't find the impulse responses, connected to a certain preset.
Two questions, every idea would be great!
- Is there any way to teach Space Designer Presets where to look for impulse respones. I can load IR samples directly and create a new preset, but I can't use my old ones.
- Is it possible to install Logic from scratch over an existing version? Or how should I de-install everything connected with Logic and then install a fresh version from CD?
Thank you again,
Joern