After the last patch i noticed this. Some sprites look like black squares with red ERROR on them.
http://imageshack.us/photo/my-images/830/2012010500003y.jpg
http://imageshack.us/photo/my-images/408/2012010500002y.jpg
http://imageshack.us/photo/my-images/195/2012010500001.jpg/
That's where i saw it:
- Poison and freeze traps
- Healing with health capsule
- Mender or silkwing healing enemy
- Dying silkwing
- Shivermist and Voltaic Tempest bombs
The first thing to do when that happens is reinstall