[LAU] midi triggering delay

Hi all, I'm trying to get my usb midi keyboard (an edirol PCR 800) working with my good laptop (a 1400 MHz core 2 thinkpad X61s). I have jackd running with 8 msec latency and no xruns using an onboard intel HDA sound card. When I hook up qsynth (fluidsynth) to the keyboard's alsa midi output, the notes are triggered with a slight (<0.1s?), and variable time delay. Sometimes the note plays immediately on pressing the key; sometimes there is a noticeable delay. This does not happen when I use the same setup on my old laptop (a 1400 Mhz single core dell). The OS is debian testing at the moment, but I have had the same problem on this laptop with both ubuntu jaunty and a fairly recent version of linux mint. Does anyone have any idea what might be happening, or what I can do to narrow down the cause of the problem a bit further? My /proc/interrupts, lsusb, and lspci are pasted below. Cheers, andy baxter andy@monkey:~$ cat /proc/interrupts CPU0 CPU1 0: 1207873 1669765 IO-APIC-edge timer 1: 2473 1983 IO-APIC-edge i8042 8: 1 0 IO-APIC-edge rtc0 9: 19517 11123 IO-APIC-fasteoi acpi 12: 25255 22957 IO-APIC-edge i8042 14: 0 0 IO-APIC-edge ide0 16: 380396 233180 IO-APIC-fasteoi uhci_hcd:usb4, yenta 17: 829711 532117 IO-APIC-fasteoi uhci_hcd:usb5, ohci1394, HDA Intel 18: 0 0 IO-APIC-fasteoi mmc0 19: 2 0 IO-APIC-fasteoi ehci_hcd:usb6 20: 18 17 IO-APIC-fasteoi uhci_hcd:usb1 21: 0 0 IO-APIC-fasteoi uhci_hcd:usb2 22: 305246 302929 IO-APIC-fasteoi ehci_hcd:usb3 220: 8566 7543 PCI-MSI-edge eth0 221: 27049 24430 PCI-MSI-edge ahci NMI: 0 0 Non-maskable interrupts LOC: 426040 660568 Local timer interrupts RES: 2036860 2297232 Rescheduling interrupts CAL: 7278 7718 function call interrupts TLB: 14422 14326 TLB shootdowns TRM: 0 0 Thermal event interrupts SPU: 0 0 Spurious interrupts ERR: 0 MIS: 0 andy@monkey:~$ lsusb Bus 001 Device 003: ID 0483:2016 SGS Thomson Microelectronics Fingerprint Reader Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 002: ID 0582:0033 Roland Corp. EDIROL PCR Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 003: ID 07ab:fcdf Freecom Technologies Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 006 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub andy@monkey:~$ lspci 00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 0c) 00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c) 00:02.1 Display controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c) 00:19.0 Ethernet controller: Intel Corporation 82566MM Gigabit Network Connection (rev 03) 00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 03) 00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #5 (rev 03) 00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 03) 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03) 00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03) 00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 03) 00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 03) 00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 03) 00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03) 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f3) 00:1f.0 ISA bridge: Intel Corporation 82801HBM (ICH8M-E) LPC Interface Controller (rev 03) 00:1f.1 IDE interface: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 03) 00:1f.2 SATA controller: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) SATA AHCI Controller (rev 03) 00:1f.3 SMBus: Intel Corporation 82801H (ICH8 Family) SMBus Controller (rev 03) 03:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN [Kedron] Network Connection (rev 61) 05:00.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev ba) 05:00.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 04) 05:00.2 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 21)