Re: 188.16 - Memory leak and gaphical "corruption"
Your log indicates you're running 180.11 and not .16.
If the driver was leaking pixmap cache, the memory usage wouldn't be in the client application. At first glance, it looks like the abnormal memory usage is caused by a bug in plasma.
What happens to the memory usage of plasma if you VT-switch out and back in the X server?