emu10k1 driver BUG()

I'm trying to use rawrec with a SB Live, but I get a kernel BUG():

al@mater:~$ rawrec file.raw
 kernel BUG at audio.c:1474!
 invalid operand: 0000
 CPU:    0
 EIP:    0010:[<e289a343>]    Not tainted
 EFLAGS: 00010082
 eax: 00000029   ebx: df979d08   ecx: c0332958   edx: de718000
 esi: 0000e000   edi: 00005555   ebp: 00003556   esp: de719ecc
 ds: 0018   es: 0018   ss: 0018
 Process rawrec (pid: 558, stackpage=de719000)
 Stack: e28a29a0 0000e000 00005555 00000202 df979cc0 00000000 bffff038 0000ffff
        00018000 0001c000 00010000 00014000 e289962e df979cc0 c0045004 ffffffe7
        bffff038 dfb9c0c0 c168d340 e28a49c0 dfb9c0c0 00000000 df979cc0 00000000
 Call Trace: [<e28a29a0>] [<e289962e>] [<e28a49c0>] [<c0135d42>] [<c0142ee9>]
    [<c01086e3>]

 Code: 0f 0b c5 05 80 29 8a e2 83 c4 0c 89 f6 5b 5e 5f 5d 83 c4 14
 Segmentation fault

In line 1474 I see

if (buffer->size % buffer->fragment_size)

	BUG();

I've added a printk just before the BUG() call and I got this:

buffer->size = 57344; buffer->fragment_size = 21845

Kernel version is 2.4.19-pre7-ac2, same with 2.4.19-pre3-ac6 + preempt patch. I've not tried with earlier versions, nor 2.5.x tree.
Attached file is an 'lspci -vv' output relative to the sound card.

Loaded modules are:

al@mater:~$ /sbin/lsmod 
Module                  Size  Used by    Tainted: PF 
smbfs                  33216   2 (autoclean)
mousedev                3968   1
usb-storage            21116   0 (unused)
hid                    12992   0 (unused)
input                   3456   0 [mousedev hid]
usb-uhci               22404   0 (unused)
usbcore                37600   0 [usb-storage hid usb-uhci]
emu10k1                59328   0
ac97_codec              9696   0 [emu10k1]
sound                  55276   0 [emu10k1]
8139too                14272   1
mii                     1136   0 [8139too]

Regards,

Luca

00:0b.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 04)
Subsystem: Creative Labs CT4620 SBLive!
Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
Status: Cap+ 66Mhz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Latency: 32 (500ns min, 5000ns max)
Interrupt: pin A routed to IRQ 12
Region 0: I/O ports at d000 [size=32]
Capabilities: [dc] Power Management version 1
Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
Status: D0 PME-Enable- DSel=0 DScale=0 PME-