I've worked out the problem. My Armory data directory is on the other drive too and I had it linked into the .armory directory in my home folder. Running Armory from the command line with the -datadir option fixes the problem. What's odd is that I'm sure this arrangement worked with a previous version because I didn't have space on my SSD when I caught up the Armory data with the blockchain. It hadn't been run for quite some time too.

Anyway, all is well. I'll just modify my .desktop file with the command line options. Thanks for helping me out.