On the forum (https://forums.oracle.com/forums/thread.jspa?forumID=1385&threadID=2467388) a user reported a general slowness after 6 to 15 minutes of use (with SB 1.0 GA, 1.1 b07 and b11).
He runs Win XP 32-bit with:
NVIDIA GeForce 6600
Dual Core Intel pentium 4 cpu 3.00GHz
4GB RAM (3 Usable)

I went able to reproduce it with 1.1 b12 on the same OS, Win XP + SP3, 32-bit. My video adapter is an NVidia Quadro E-Series.
Constructing the attached FXML layout is enough to reproduce the issue.
For some reason I didn't encounter any issue when taking the same steps on :
- Windows 7 + SP1, 64-bit
- Windows 7 + SP1, 7 32-bit

In both cases the failure is seen the hardware acceleration is enabled.