Q: Associate device with id?

You need to turn on automatic downloads, use iTunes Match or download past purchases : http://support.apple.com/kb/HT4627

I have the same problem, any update?

I have the same problem here ... I recently bought my son an ipad and it is not pulling down all of his apps from his ipod.  How do I associate this ipad with his accountÉ; ... My compuer is authorized, but iTunes will not associate the ipad with his iTunes account.  What he really wants is to have all of the Minecraft worlds that he built on his ipod, show up on his ipad ... how do I get him thisÉ

Not sure what you mean by 'pulling down all of his apps from his iPod' ? If he wants to have the same progress on those games that hs has on the iPod then have you tried backing up the iPod to his computer's iTunes and then restoring that backup onto the iPad (which will overwrite the current contents of the iPad) ? Some games the progress is only stored in the actual game on the device, it isn't synced via the account, so to play at the same level on a different device you need to backup the first device and restore onto the second.

Backups and restores : http://support.apple.com/kb/HT4079

Associating a device or computer to a device : http://support.apple.com/kb/HT4627 (that won't achieve what you want)