Win7 / GTX460
Short description of error
Modifiers used after Decimate with Planar option behave wrong. Seems like part of decimation work after those modifiers which should not happen. Using Smooth after Decimate should only deform mesh but topology changes randomly.
Exact steps for others to reproduce the error
Modify Repeat value in Smooth modifier. Topology of mesh changes. Note that same value can result completely different topology.
Modify Factor value in Cast modifier. Topology changes despite modifier is disabled.
Turn of Smooth modifier and enable Cast modifier.
Change Factor value. Topology is jiggling.