Mike, as you continue to add and modify files through the day those changes are being saved to your database – or at least DEVONthink is attempting to save the changes to your hard drive.
A Mac that frequently crashes isn’t a good working environment. Your Mac is designed to be stable. It’s time to do some diagnostics.
First, open Activity Monitor and look at the amount of free hard drive space that’s available. Apple engineers recommend at least 10% to 15% of the hard drive space should be free so that there’s room for the operating system and applications to write temporary files to disk (20% is better). Why? Because if your computer runs out of free space the operating system itself could start overwriting files, resulting in data loss and errors. That’s bad. I assume yours is an older computer, perhaps with a relatively small hard drive. If you are low on drive space, housekeeping is in order. Delete or archive to CD or DVD files that you rarely need or use, so that there’s “breathing room” on the drive.
Let’s eliminate one possibility for an unchanging database. In the Finder, select your database file, with the extension “.dtBase” as you are running DT Pro. Press Command-I to open the Info panel. Look at Ownership & Permissions (if you are running Tiger) or Sharing & Permissions (if you are running Leopard). You should have read & write permissions for this file; if read only, changes cannot be saved to it. If the permissions are incorrect, you can edit them to give yourself read & write permission.
Next, run Apple’s Disk Utility application. Run the repair permissions and disk verify procedures. If the disk verify routine finds errors, follow Apple’s recommendation to insert your Installation disc and repair the disk directory.
Hardware problems are fairly rare, but this possibility should be checked. Your Installation disc contains a routine to check hardware components in your computer.
Have you been running OS X maintenance? A utility such as OnyX or C*cktail can run a number of them that are built-in to your operating system. Run the cron scripts, rotate the logs and – I would recommend – clean out the existing system and user cache files. Corrupt cache files can cause problems. You might also check out your fonts, as corrupt fonts can cause numerous problems.
Fingers crossed, these checks and maintenance operations may identify the problem and/or make your computer much more stable.
Whenever I’ve made significant changes to a database, such as adding lots of new content or spending time writing something important, I don’t want to wait for an automatic backup. At break time, I’ll force a backup. If there’s plenty of free hard drive space, I’ll run Scripts > Export > Backup Archive. When I return from break the database has been verified, optimized and I’ve got current internal and external backup. Otherwise, at that break I’ll run Tools > Verify & Repair to check database integrity, followed by Tools > Backup & Optimize, so that I’ve got current internal backup. If something goes wrong, I haven’t lost my work. I really recommend running Backup Archive to produce a compressed and dated archive file once in a while, then storing that on an external medium such as a CD or DVD. That’s insurance against a catastrophic failure of your computer’s hard drive.