atacontrol create RAID0+1 = panic

atacontrol is causing a panic when I attempt to create a RAID0+1 array. 
  I refreshed the sources shortly after midnight and did a fresh build 
this morning because in my prior build's atacontrol was causing a panic 
when I attempted to delete a RAID0 array.

Please let me know if any information besides the following is required:

saturn# atacontrol create RAID0+1 2000 ad4 ad6 ad2 ad3
ar0: 381564MB <ATA RAID0+1 array> [48624/255/63] status: READY subdisks:
  disk0 READY on ad4 at ata2-master
  disk1 READY on ad6 at ata3-master
  disk2 READY on ad2 at ata1-master
  disk3 READY on ad3 at ata1-slave
Slab at 0xc4770ccc, freei 0 = 0.
panic: Duplicate free of item 0xc4a0d000 from zone 0xc10261c0(2048)

at line 271 in file /usr/src/sys/vm/uma_dbg.c
cpuid = 0;
Debugger("panic")
Stopped at      Debugger+0x46:  xchgl   %ebx,in_Debugger.0
db>


The machine is a ASUS P4C800-E Deluxe with Hyper Threading enabled, 
EIDE/SATA enhanced mode disabled (aka; compatibility/legacy), and the 
onboard Promise RAID is configured for standard IDE (non-RAID).

    Thanks.