I have a current time line that I had a file that I temp tried, but was in the wrong file with the others. So I deleted it. Now when I open this project I always have to click om "Ignore all missing files & leave them offline". Why doesn't Vegas leave them offline?
Because the event has been on the timeline for that project, Vegas Pro still looks for it - and the 'missing file' alert props up because it has been deleted - or even moved to another folder.
To solve that for deleted/removed media, go to the Project Media window (under View / Window) and in the Project Media window click on the top LH icon "Remove All Unused Media from Project" which will then leave only the current media on the timeline in Vegas Pro's memory for that project.