Try some performance tweaking.
Get Beta 16 (if you haven't already) and read the
Release Notes.
Download and install PT3.
Have a look at:
Performance Tuning: Hard Drives
Performance Tuning PostgreSQL.
Also use the Database menu to do the 'HouseKeeping' on your database.
You may find that enabling 'enhance HUD performance' on HUD Options helps too, although it shouldn't be so necessary in Beta 16.