Without quota enabled everything works well. But as soon as I enable quota on my /home and open and close a file on / my kernel oopses:

Jan 12 10:54:20 feivel kernel: [  147.999029] kernel BUG at /build/buildd-linux-2.6_2.6.32-5-amd64-9RvY2G/linux-2.6-2.6.32/debian/build/source_amd64_none/fs/quota/dquot.c:1398!
Jan 12 10:54:20 feivel kernel: [  147.999037] invalid opcode: 0000 [#1] SMP 
Jan 12 10:54:20 feivel kernel: [  147.999042] last sysfs file: /sys/devices/pci0000:00/0000:00:1c.5/0000:0b:00.0/net/eth0/carrier
Jan 12 10:54:20 feivel kernel: [  147.999047] CPU 7 
Jan 12 10:54:20 feivel kernel: [  147.999050] Modules linked in: radeon ttm drm_kms_helper drm agpgart i2c_algo_bit sco bridge stp bnep rfcomm l2cap crc16 ppdev lp parport advantechwdt acpi_cpufreq cpufreq_stats cpufreq_conservative cpufreq_powersave cpufreq_userspace kvm_intel kvm uinput quota_v2 quota_tree fuse loop firewire_sbp2 btusb snd_hda_codec_atihdmi joydev bluetooth snd_hda_codec_idt snd_hda_intel snd_hda_codec arc4 ecb snd_hwdep uvcvideo snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_midi iwlagn snd_rawmidi snd_seq_midi_event snd_seq iwlcore videodev v4l1_compat v4l2_compat_ioctl32 mac80211 snd_timer snd_seq_device i2c_i801 snd cfg80211 soundcore psmouse evdev dell_laptop serio_raw pcspkr snd_page_alloc wmi i2c_core dcdbas rfkill processor battery ac ext3 jbd mbcache sha256_generic cryptd aes_x86_64 aes_generic cbc dm_crypt dm_mod usbhid hid sg sr_mod sd_mod cdrom crc_t10dif sdhci_pci firewire_ohci sdhci ahci video mmc_core libata firewire_core output scsi_mod ehci_hcd crc_itu_t led_class r8169 mii usbcore
Jan 12 10:54:20 feivel kernel: nls_base button thermal fan thermal_sys [last unloaded: scsi_wait_scan]
Jan 12 10:54:20 feivel kernel: [  147.999193] Pid: 2683, comm: vi Not tainted 2.6.32-trunk-amd64 #1 Studio 1557
Jan 12 10:54:20 feivel kernel: [  147.999198] RIP: 0010:[<ffffffff8112b43d>]  [<ffffffff8112b43d>] dquot_transfer+0x123/0x49d
Jan 12 10:54:20 feivel kernel: [  147.999213] RSP: 0018:ffff880134ecdd98  EFLAGS: 00010246
Jan 12 10:54:20 feivel kernel: [  147.999217] RAX: 0000000000000000 RBX: ffff88012cb61d50 RCX: 00007fd1a3bb9000
Jan 12 10:54:20 feivel kernel: [  147.999222] RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff88012cb61d50
Jan 12 10:54:20 feivel kernel: [  147.999227] RBP: ffff88012cb61ca0 R08: 0000000000000000 R09: ffff880134ecdee8
Jan 12 10:54:20 feivel kernel: [  147.999232] R10: 0000005000000001 R11: 0000000000000000 R12: 0000000000000001
Jan 12 10:54:20 feivel kernel: [  147.999236] R13: 0000000000000000 R14: 0000000000001846 R15: 0000000000000000
Jan 12 10:54:20 feivel kernel: [  147.999242] FS:  00007fd1a3b9e790(0000) GS:ffff8800055c0000(0000) knlGS:0000000000000000
Jan 12 10:54:20 feivel kernel: [  147.999248] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jan 12 10:54:20 feivel kernel: [  147.999252] CR2: 000000000044aab0 CR3: 0000000133919000 CR4: 00000000000026e0
Jan 12 10:54:20 feivel kernel: [  147.999257] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Jan 12 10:54:20 feivel kernel: [  147.999262] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Jan 12 10:54:20 feivel kernel: [  147.999268] Process vi (pid: 2683, threadinfo ffff880134ecc000, task ffff8801349ba350)
Jan 12 10:54:20 feivel kernel: [  147.999272] Stack:
Jan 12 10:54:20 feivel kernel: [  147.999274]  ffff8801376ca000 ffff8801360b8068 ffff88012cb64000 0000000000000000
Jan 12 10:54:20 feivel kernel: [  147.999281] <0> 0000000000000000 0000000000000000 ffff8801360bd800 ffffffff8112a3ad
Jan 12 10:54:20 feivel kernel: [  147.999289] <0> ffff88012cb61ca0 ffff8801360bd800 00000000ffff0000 ffffffff8112b8be
Jan 12 10:54:20 feivel kernel: [  147.999297] Call Trace:
Jan 12 10:54:20 feivel kernel: [  147.999304]  [<ffffffff8112a3ad>] ? dqput+0x89/0x21a
Jan 12 10:54:20 feivel kernel: [  147.999311]  [<ffffffff8112b8be>] ? dquot_initialize+0x107/0x115
Jan 12 10:54:20 feivel kernel: [  147.999318]  [<ffffffff8112856e>] ? vfs_dq_transfer+0x6a/0x86
Jan 12 10:54:20 feivel kernel: [  147.999334]  [<ffffffffa01ba3ee>] ? ext3_setattr+0x9e/0x1c9 [ext3]
Jan 12 10:54:20 feivel kernel: [  147.999343]  [<ffffffff810fe397>] ? notify_change+0x180/0x2c5
Jan 12 10:54:20 feivel kernel: [  147.999351]  [<ffffffff810eab35>] ? chown_common+0x66/0x7c
Jan 12 10:54:20 feivel kernel: [  147.999357]  [<ffffffff810eaba7>] ? sys_fchown+0x5c/0x86
Jan 12 10:54:20 feivel kernel: [  147.999367]  [<ffffffff81010b02>] ? system_call_fastpath+0x16/0x1b
Jan 12 10:54:20 feivel kernel: [  147.999372] Code: 00 48 89 ef e8 ab 3b fc ff 48 89 df 49 89 c5 e8 45 b7 1b 00 48 8b 85 00 01 00 00 48 8b 40 40 48 8b 80 88 00 00 00 48 85 c0 75 04 <0f> 0b eb fe 48 89 ef ff d0 4c 8b 30 66 ff 85 b0 00 00 00 4b 8d 
Jan 12 10:54:20 feivel kernel: [  147.999425] RIP  [<ffffffff8112b43d>] dquot_transfer+0x123/0x49d
Jan 12 10:54:20 feivel kernel: [  147.999433]  RSP <ffff880134ecdd98>
Jan 12 10:54:20 feivel kernel: [  147.999438] ---[ end trace e24f7f473235aecb ]---

Michael