I thought for sure I had figured it out...I realized that when my IT department updated my service pack, they updated my MS Office service pack and I noticed that I was still running SP1 for Project in the licence info. So today I had them update my service pack for Project to the latest CU, but unfortunately the problem is still occurring, whether I send a file to the printer or Adobe Acrobat.

I've scoured the net and nobody seems to have reported this problem, yet I can replicate it on a colleague's computer.

I guess I'll just have to work around the issue.