MIDI controllers appearing, disappearing?

[divojulio]

Hello everyone! I am new to the board, although I have lurked here before. Actually this is my first issue I haven't been able to remedy by just searching, and that has actually required asking. Nevertheless, I do want to thank everyone in advance for reading and giving any advice!
I'm using Ubuntu, which I am very familiar with. Up till a recent reinstall, I was using an Akai LPK25 USB MIDI controller with LMMS, and it worked just great. After the reinstall, however, it started doing this strange thing whereby it now (according to the PC) blinks in and out of existence whenever plugged into the computer. It will pop-up in LMMS and Jack for a fraction of a second and then disappear again. The readout of KMidimon looks like this:

0,0.0133,0:1,,ALSA Port subscribed,0:1,128:0,
0,0.0184,0:1,,ALSA Client start,14,,
0,0.0211,0:1,,ALSA Port start,14:0,,
65,0.9759,0:1,,ALSA Client start,20,,
65,0.9779,0:1,,ALSA Port start,20:0,,
137,0.9793,0:1,,ALSA Port exit,20:0,,
137,0.9809,0:1,,ALSA Client exit,20,,
420,0.9843,0:1,,ALSA Client start,20,,
420,0.9872,0:1,,ALSA Port start,20:0,,
497,1.1173,0:1,,ALSA Port exit,20:0,,
497,1.1203,0:1,,ALSA Client exit,20,,
775,1.6172,0:1,,ALSA Client start,20,,
775,1.6233,0:1,,ALSA Port start,20:0,,
862,1.7990,0:1,,ALSA Port exit,20:0,,
862,1.8146,0:1,,ALSA Client exit,20,,

...and so on into infinity. I have also acquired an M-Audio Keystation 49e since the reinstall, and get the same behavior from it. I am using the latest stable release of Natty, and a Compaq Presario f700 Laptop. At this point, I am at a loss for what to do next, though it seems pretty clearly to be a software issue.

Anyway, I would greatly appreciate any help!
Thanks!

[raboof]

anything interesting in /var/log/syslog or /var/log/message or dmesg?

[divojulio]

Hi Raboof! Thanks for the lead. /var/log/syslog does at least have some information that could help, although I'm not entirely sure how to decode it. Here's what comes up when I plug in a keyboard:

May 13 10:19:16 linux-laptop kernel: [ 2561.110067] usb 2-2: new full speed USB device using ohci_hcd and address 4
May 13 10:19:16 linux-laptop kernel: [ 2561.484441] hub 2-0:1.0: port 2 disabled by hub (EMI?), re-enabling...
May 13 10:19:16 linux-laptop kernel: [ 2561.484458] usb 2-2: USB disconnect, address 4
May 13 10:19:16 linux-laptop pulseaudio[1525]: udev-util.c: Failed to get card object.
May 13 10:19:16 linux-laptop pulseaudio[1525]: module-alsa-card.c: Failed to find a working profile.
May 13 10:19:16 linux-laptop pulseaudio[1525]: module.c: Failed to load module "module-alsa-card" (argument: "device_id="1" name="usb-AKAI_professional_LLC_LPK25-00-LPK25" card_name="alsa_card.usb-AKAI_professional_LLC_LPK25-00-LPK25" tsched=yes ignore_dB=no card_properties="module-udev-detect.discovered=1""): initialization failed.
May 13 10:19:16 linux-laptop kernel: [ 2561.820057] usb 2-2: new full speed USB device using ohci_hcd and address 5
May 13 10:19:17 linux-laptop kernel: [ 2562.420141] usb 2-2: device not accepting address 5, error -62
May 13 10:19:17 linux-laptop kernel: [ 2562.480089] hub 2-0:1.0: unable to enumerate USB device on port 2
May 13 10:19:17 linux-laptop kernel: [ 2562.900055] usb 2-2: new full speed USB device using ohci_hcd and address 7
May 13 10:19:18 linux-laptop kernel: [ 2563.290110] hub 2-0:1.0: port 2 disabled by hub (EMI?), re-enabling...
May 13 10:19:18 linux-laptop kernel: [ 2563.290127] usb 2-2: USB disconnect, address 7
May 13 10:19:18 linux-laptop pulseaudio[1525]: udev-util.c: Failed to get card object.
May 13 10:19:18 linux-laptop pulseaudio[1525]: module-alsa-card.c: Failed to find a working profile.
May 13 10:19:18 linux-laptop pulseaudio[1525]: module.c: Failed to load module "module-alsa-card" (argument: "device_id="1" name="usb-AKAI_professional_LLC_LPK25-00-LPK25" card_name="alsa_card.usb-AKAI_professional_LLC_LPK25-00-LPK25" tsched=yes ignore_dB=no card_properties="module-udev-detect.discovered=1""): initialization failed.
May 13 10:19:18 linux-laptop kernel: [ 2563.650065] usb 2-2: new full speed USB device using ohci_hcd and address 8

...and so on. Hopefully this will help clarify the issue? Thanks

[raboof]

Hi Raboof! Thanks for the lead. /var/log/syslog does at least have some information that could help, although I'm not entirely sure how to decode it. Here's what comes up when I plug in a keyboard:

It's not obvious to me what's going wrong, but this might be something to google for. For example, I saw at https://bugs.launchpad.net/ubuntu/+sour ... +bug/54273 that you might try 'rmmod ehci_hcd' - USB1.1 should be OK for MIDI.