After a quick search I discovered that the CrashPlan backup service was exceeding its memory allocation. It was trivial to change the allocation from 512m to 1024m:
- Stop the CrashPlan Backup Service
- Launch notepad as Adminitrator
- Edit C:\Program Files\CrashPlan\CrashPlanService.ini
- Change -Xmx512m to -Xmx1024m
Answer was taken from http://homeservershow.com/forums/index.php?/topic/3978-is-your-crash-plan-crashing.