SENUTI: hiccups, jumps, and spits? Flawed Transfer...?!?

I've got a big mess on my hands, and I'm looking for advice.

I've always had a lot of music: (though I suppose that's relative): about 4500 songs... (these are backed-up on DVD), PLUS in August I briefly found a music critic boyfriend that added another 1500 songs to my library (rare and special songs that are not backed-up, I only back up once every 6 months).

I also have songs, films, and television shows I've purchased from the iTunes store. (thus DRM protected)

I didn't have any problems until my computer upgraded iTunes 7 to iTunes 8... then I noticed that little exclamation points started appearing next to my music: missing files. (oh nooooo!)

I thought it was a problem with ME, until I bought an entire season of a TV show on iTunes, and the next time I booted up my computer, it was missing. Afraid that my media collection was starting to look like Swiss cheese, I found a program to get my music off the iPod itself (still a fully intact library) and onto my computer. After un-installing iTunes 8, (and re-installing iTunes 6), I decided to use a program called PodWorks to move my library from the iPod back to the library. This didn't copy my entire library (only 1300 songs total). At this point I decided to use a similar program called Senuti. Senuti seemed to get everything. At this point I had multiple copies of files (17,000 files in total: 120GB of info, blech!), so I bought a copy of iDupe, to remove the duplicates. It worked beautifully,

...but there's a problem.

Now when I listen to my music, I notice that all the files are VERY flawed. There are hiccups, jumps, spits, and sometimes you get halfway through the song and iTunes just moves to the next song. The only possible explanation (I assume) is that the program I used to get the info off my iPod didn't work properly.

In essence, I've lost most of my music. I think the good plan would be to delete my entire library, then find a REAL program that works to get my stuff safely off the iPod. Can you tell me of a good program that would do this?? (presumably NOT PodWorks, NOT Senuti...)

Here are my computer specs: (I am a Mac User, running OS 10.5.6)

Model Name: iBook G4
Model Identifier: PowerBook6,5
Processor Name: PowerPC G4 (1.2)
Processor Speed: 1.2 GHz
Number Of CPUs: 1
L2 Cache (per CPU): 512 KB
Memory: 768 MB
Bus Speed: 133 MHz
Boot ROM Version: 4.8.7f1

I'm running the newest OS. Perhaps I should go back to the old one for Senuti to run properly....???