Using Ubuntu mainline packages and config on Ubuntu Karmic with bluez 4.51-0ubuntu2:

http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2010-03-27-karmic/

Log of oops:
5401 Mar 29 12:20:58 tlb-server hidd: New HID device 00:07:61:FE:30:CA (Logitech         Keyboard)
5402 Mar 29 12:20:58 tlb-server kernel: [  196.301766] input: Logitech         Keyboard as /devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1:1.0/bluetooth/hci0/hci0:41/input11
5403 Mar 29 12:20:58 tlb-server kernel: [  196.301847] generic-bluetooth 0005:046D:B30A.0001: input,hidraw0: BLUETOOTH HID v1.1b Mouse [Logitech         Keyboard] on 00:04:61:82:4C:1C
5404 Mar 29 12:21:15 tlb-server NetworkManager: bluez_manager_bdaddr_removed_cb: BT device 00:07:61:FE:30:CA removed
5405 Mar 29 12:21:15 tlb-server kernel: [  213.880154] ------------[ cut here ]------------
5406 Mar 29 12:21:15 tlb-server kernel: [  213.880159] kernel BUG at /home/kernel-ppa/mainline/build/mm/memory.c:133!
5407 Mar 29 12:21:15 tlb-server kernel: [  213.880162] invalid opcode: 0000 [#1] SMP
5408 Mar 29 12:21:15 tlb-server kernel: [  213.880165] last sysfs file: /sys/devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1:1.0/bluetooth/hci0/hci0:41/input11/event11/uevent
5409 Mar 29 12:21:15 tlb-server kernel: [  213.880168] CPU 0
5410 Mar 29 12:21:15 tlb-server kernel: [  213.880169] Modules linked in: joydev hidp binfmt_misc ppdev vboxnetadp vboxnetflt vboxdrv bridge stp bnep usblp snd_hda_codec_intelhdmi snd_hda_codec_idt snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_m
5411 Mar 29 12:21:15 tlb-server kernel: [  213.880216]
5412 Mar 29 12:21:15 tlb-server kernel: [  213.880219] Pid: 2772, comm: khidpd_046db30a Not tainted 2.6.34-999-generic #201003271003 DG45FC/
5413 Mar 29 12:21:15 tlb-server kernel: [  213.880222] RIP: 0010:[<ffffffff810fb728>]  [<ffffffff810fb728>] __sync_task_rss_stat+0x48/0x50
5414 Mar 29 12:21:15 tlb-server kernel: [  213.880230] RSP: 0018:ffff88011219bed0  EFLAGS: 00010246
5415 Mar 29 12:21:15 tlb-server kernel: [  213.880232] RAX: 0000000000000006 RBX: ffff8801258ecae0 RCX: 0000000000000000
5416 Mar 29 12:21:15 tlb-server kernel: [  213.880235] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801258ec4d0
5417 Mar 29 12:21:15 tlb-server kernel: [  213.880237] RBP: ffff88011219bed0 R08: 0000000000000000 R09: 0000000000000001
5418 Mar 29 12:21:15 tlb-server kernel: [  213.880239] R10: ffff880001e15720 R11: 0000000000000000 R12: 0000000000000000
5419 Mar 29 12:21:15 tlb-server kernel: [  213.880242] R13: ffff8801258ec4d0 R14: 0000000000000000 R15: 0000000000000000
5420 Mar 29 12:21:15 tlb-server kernel: [  213.880245] FS:  00007f2753c866f0(0000) GS:ffff880001e00000(0000) knlGS:0000000000000000
5421 Mar 29 12:21:15 tlb-server kernel: [  213.880247] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
5422 Mar 29 12:21:15 tlb-server kernel: [  213.880250] CR2: 00007f80fd2da000 CR3: 0000000001a29000 CR4: 00000000000406f0
5423 Mar 29 12:21:15 tlb-server kernel: [  213.880252] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
5424 Mar 29 12:21:15 tlb-server kernel: [  213.880255] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
5425 Mar 29 12:21:15 tlb-server kernel: [  213.880257] Process khidpd_046db30a (pid: 2772, threadinfo ffff88011219a000, task ffff8801258ec4d0)
5426 Mar 29 12:21:15 tlb-server kernel: [  213.880259] Stack:
5427 Mar 29 12:21:15 tlb-server kernel: [  213.880261]  ffff88011219bee0 ffffffff810fb739 ffff88011219bf40 ffffffff8105caec
5428 Mar 29 12:21:15 tlb-server kernel: [  213.880265] <0> ffffffff8104b320 0000000000000000 dead000000200200 0000000000000001
5429 Mar 29 12:21:15 tlb-server kernel: [  213.880269] <0> ffff880124267100 0000000000000000 0000000000000000 0000000000000000
5430 Mar 29 12:21:15 tlb-server kernel: [  213.880274] Call Trace:
5431 Mar 29 12:21:15 tlb-server kernel: [  213.880278]  [<ffffffff810fb739>] 


sync_mm_rss+0x9/0x10
5432 Mar 29 12:21:15 tlb-server kernel: [  213.880282]  [<ffffffff8105caec>] do_exit+0xdc/0x3b0
5433 Mar 29 12:21:15 tlb-server kernel: [  213.880285]  [<ffffffff8104b320>] ? default_wake_function+0x0/0x10
5434 Mar 29 12:21:15 tlb-server kernel: [  213.880289]  [<ffffffff8100aceb>] kernel_thread_helper+0xb/0x10
5435 Mar 29 12:21:15 tlb-server kernel: [  213.880295]  [<ffffffffa02330c0>] ? hidp_session+0x0/0x3f0 [hidp]
5436 Mar 29 12:21:15 tlb-server kernel: [  213.880298]  [<ffffffff8100ace0>] ? kernel_thread_helper+0x0/0x10
5437 Mar 29 12:21:15 tlb-server kernel: [  213.880300] Code: 80 02 00 00 00 00 00 00 c9 c3 48 85 f6 74 1c 48 63 d0 48 8d 84 ce a0 02 00 00 f0 48 01 10 c7 84 8f 84 02 00 00 00 00 00 00 eb c9 <0f> 0b eb fe 0f 1f 40 00 55 48 89 e5 e8 a7 ff ff ff c9 c3 0f 1
5438 Mar 29 12:21:15 tlb-server kernel: [  213.880337] RIP  [<ffffffff810fb728>] __sync_task_rss_stat+0x48/0x50
5439 Mar 29 12:21:15 tlb-server kernel: [  213.880341]  RSP <ffff88011219bed0>
5440 Mar 29 12:21:15 tlb-server kernel: [  213.880348] ---[ end trace 16caa451233cb36b ]---
5441 Mar 29 12:21:15 tlb-server kernel: [  213.880350] Fixing recursive fault but reboot is needed!
5442 Mar 29 12:21:29 tlb-server NetworkManager: bluez_manager_bdaddr_removed_cb: BT device 00:07:61:FE:30:CA removed