Hi everybody, i'm having again problems with usb. Here is what happened: i was running kernel 2.6.8-1.521 with acpi turned off on boot by grub.conf. It was good enough, i could mount usb memory sticks and usb drives. I also have a ipaq though, and i would like to connect it via usb. Since i need to patch ipaq driver in order to get it working, i installed kernel source and realized that there is no (at least i couldn't find it) kernel source with number 2.6.8-1.521 So i installed back kernel 2.6.5-1.358 with source. I left acpi=off in grub.conf and got a lot of error messages at boot saying: Nov 2 11:13:01 brunettie kernel: ehci_hcd 0000:00:1d.7: USB 2.0 enabled, EHCI 1.00, driver 2003-Dec-29 Nov 2 11:13:01 brunettie kernel: hub 4-0:1.0: USB hub found Nov 2 11:13:01 brunettie kernel: hub 4-0:1.0: 6 ports detected Nov 2 11:13:01 brunettie kernel: hub 2-0:1.0: connect-debounce failed, port 2 disabled And also: hub 4-0:1.0: connect-debounce failed, port 4 disabled If i turn on acpi with kernel 2.6.5-1.358, no errors like those but usb storage definitely doesn't work and i can't use any kind of memory stick or usb disks. Oddly enough, i get the usual message in /var/log/messages: Nov 2 11:34:48 brunettie kernel: usb 2-2: new full speed USB device using address 2 Nov 2 11:34:53 brunettie kernel: usb 2-2: control timeout on ep0out Nov 2 11:34:53 brunettie kernel: uhci_hcd 0000:00:1d.1: Unlink after no-IRQ? Different ACPI or APIC settings may help. The very same thing happens with 'noapic'. Any hint? I guess that the best thing to do would be find and install a kernel source 2.6.8-1.521, but i couldn't find it. Which is weird: i only update kernels via yum, but now looks like there are no kernel 2.6.8-1.521 around. Thanks all E.