usermng hangs when i try to edit webhosting settings

[Lumbo]

When i try to change a setting for a domain in the "Webhosting Settings" tab the page displays the usual "please wait while loading" message, seems to wait for a minute and then displays a blank page.

TOP shows usermng with +100% cpu and the systemload jumps to higher than 3.00 untill the white page is displayed, then usermng closes and the load reverts to the usual 0.30


var/log/messages of my Debian Server shows the following at the time of access:


Jun 3 12:37:52 server kernel: Pid: 29494, comm: usermng Not tainted (2.6.24-etchnhalf.1-686 #1)
Jun 3 12:37:52 server kernel: EIP: 0060:[<c01a1d7e>] EFLAGS: 00000246 CPU: 1
Jun 3 12:37:52 server kernel: EIP is at vfs_quota_on_inode+0x29d/0x3be
Jun 3 12:37:52 server kernel: EAX: f7f11274 EBX: c5f2268c ECX: c5f22884 EDX: c5f2269c
Jun 3 12:37:52 server kernel: ESI: f8921114 EDI: f7f112b0 EBP: 00000000 ESP: c34e3e20
Jun 3 12:37:52 server kernel: DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Jun 3 12:37:52 server kernel: CR0: 8005003b CR2: b7f2a3f0 CR3: 37732000 CR4: 000006d0
Jun 3 12:37:52 server kernel: DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
Jun 3 12:37:52 server kernel: DR6: ffff0ff0 DR7: 00000400
Jun 3 12:37:52 server kernel: [<c01a1f49>] vfs_quota_on+0x4e/0x61
Jun 3 12:37:52 server kernel: [<c01800c6>] getname+0x59/0xad
Jun 3 12:37:52 server kernel: [<f8966323>] ext3_quota_on+0xad/0xb5 [ext3]
Jun 3 12:37:52 server kernel: [<c0198c0f>] lookup_bdev+0x5f/0x71
Jun 3 12:37:52 server kernel: [<c016207e>] invalidate_mapping_pages+0xf/0x11
Jun 3 12:37:52 server kernel: [<c01a2322>] vfs_quota_off+0x3c6/0x3de
Jun 3 12:37:52 server kernel: [<c01800c6>] getname+0x59/0xad
Jun 3 12:37:52 server kernel: [<c01a3c99>] sys_quotactl+0x36d/0x618
Jun 3 12:37:52 server kernel: [<c011bf8f>] do_page_fault+0x1f7/0x5a8
Jun 3 12:37:52 server kernel: [<c016416d>] vma_prio_tree_remove+0x48/0xc7
Jun 3 12:37:52 server kernel: [<c0103ede>] syscall_call+0x7/0xb
Jun 3 12:37:52 server kernel: =======================

My Plesk9.3 is up to date and apt-get update + apt-get upgrade show no further patches