I'm downloading through the P2P network, and Limewire used to automatically add to iTunes. I have the option checked in preferences, have restarted and re-downloaded and updated both iTunes and Limewire, so they are the latest versions. And I'm running Windows 7. It always did it before, even with Windows 7.

Anyone else have this problem?

This has happened to people before (though I think only XP or Vista users)... go into LW's options, disable adding to iTunes. Remember to click 'ok' on the iTunes config page & also again on the main options page.
Restart LW. Now open LW & go back into options, enable adding to iTunes & then once again restart LW.

I know it's a pain, but seems that disabling > re-enabling those iTunes options is often a fix.

If that doesn't help, let us know which version of LW you're using & also which version of iTunes

This has been an issue with iTunes transfers from LW on Mac OSX for years. And it was only in the past year that LW introduced this auto transfer option for Windows users, so same principle applies.

The problem generally occurs when LW is/has been super busy or lagging.