Audacity having problems importing some files

[j_winn]

I can import and edit the original music files normally, export and it's all normal when I play it back on iTunes and WMP

However for some files when, I import it again to do some more editing audacity changes the file length

The sample rate is turned to 8khz instead of the usual 44.1khz and changing that gets the speed and length correct
But also the pitch has dropped, and I can keep trying to edit the pitch to get it around what it was originally,
or just do it all again and get it right the first time with a fresh new file

But is there a fix for this problem so I wouldn't have to bother with all that nonsense?
It's not happening with all the files I've edited with audacity, but it's happening enough to become a nuisance to get the original file again

edit- also I noticed it inserts some noise at the very beginning of the files (that are altered as described above)
This noise is not present in the beginning of the original files when viewed at the highest zoom

Thanks

[kozikowski]

<<<I can import and edit the original music files normally>>>

We would all like to assume that "Original Music Files" are those you made by singing into a microphone. That's probably not true, is it?

So you started the movie well after the first act. Where, exactly, did the music files come from?

Koz

[j_winn]

My friend lets me get CD's he buys or he burns from his itunes
if that's what you're asking