JB 3.1.2 Won't Sync Apps to iTunes

[mashinhead]

I have a jailbroken 3gs running 3.1.2, but i won't sync the apps back to iTunes that are on the phone. It says the computer isn't authorized, even though it is.

I have 3 questions:

1. Is this caused by a jailbreak.
2. What is a work around where i don't loose my apps,
3. if i just hit the update button to get 3.1.3 will i loose all my apps and the jailbreak or just the jailbreak?

 

[pixelated]

Have you synced to this computer before?
Are you sure its authorised?
Could there be Apps bought from another account on your phone?
Have you selected 'transfer purchases from iphone'?
1:No
2:'transfer purchases from iphone'
3: You will lose all your apps if you haven't synced them to a computer and will lose the JB if you upgrade to 3.1.3

 

[leftyno9]

have u got appsync from cydia?