[Zubersoft]

I may need to a library backup file from you (Settings->Backup and Restore->Backup Library) with your current library to see if there is something in the database that is loading very slowly. The fact that an empty library loads quickly means it's either something in the database that is slowing things down, or a lack of system resources (memory/RAM). It's strange that a PDF is loading so much slower than a jpg file though, because if it's a database issue, I would have expected them both to take the same amount of time to load...

Mike