I'm having some problems with my iTunes library which i've never had before
I'm running a macbook with an external hard drive for music c150GB OS X 10.5.8 iTunes 10.6.3
Earlier this month iTunes told me the xml library file was corrupted and my itunes was empty

I made itunes choose a library via an .itl file from previous iTunes libraries,
the latest one was 1st july which was when i last upgraded iTunes
so I was able to restore the library but I was missing music I'd added and metadata since July
I accepted the metadata was gone and added the music again from iTunes folder
I also created some new playlists
last night I open iTunes again and it's asking me to choose a library,
I chose the July one again and the metadata and everything i re added in early Nov is no longer there

I ripped a few new cds just as a test and this morning they're still there but I expect iTunes will tell me sometime soon that i need to choose library
and the whole thing will start again
I tried to update iTunes but it says i have the latest version

So I have a few questions - is it possible to create an .itl file for backup everytime i update iTunes with music/data
is there possibly an .itl file somewhere in my folders re my update in November,
would the problem be solved by upgrading my OS thus getting the freshest iTunes (is that right),
and any ideas about why is it happening. many thanks, C