If each individually works, chances are this is power related. Make sure it has enough power (5v @ 2A should more than suffice but not all adapters marked so meet their stated rating). There are two test points on the RPi. The voltage difference between the two should be close to 5V under load. If it has sufficient power, and you can run Linux, you can check out if everything works in Linux. lsusb -v can give you more details including current draw of eac device.

> On Jul 4, 2014, at 4:45 PM, Anant Narayanan <anant@kix.in> wrote:
> 
> That worked great, thank you!
> 
> I was able to get the keyboard to work as well, but it seems there is a different bug where plugging in both a keyboard and mouse at the same time causes usb/kb to fail.
> 
> -Anant
> 
> 
>> On Tue, Jul 1, 2014 at 11:32 PM, Bakul Shah <bakul@bitblocks.com> wrote:
>> On Tue, 01 Jul 2014 23:01:53 PDT Anant Narayanan <anant@kix.in> wrote:
>> >
>> > 1. I'm trying to get a custom built kernel to boot but not having great
>> > luck, unfortunately. I got as far as "mk 'CONF=pi'" in /sys/src/9/bcm
>> > (those are the latest sources, correct?) which generated a 2M kernel named
>> > 's9pi'. I added that to the FAT partition on the standard 9pi SD card image
>> > and edited config.txt to point to it. Now, when I boot I see a rainbow
>> > pattern screen -- switching back to the 9pi kernel in config.txt makes it
>> > boot again.
>> 
>> mk should've created 9pi and s9pi.  Copy 9pi to the fat partition, not s9pi.
>> 
>> > What am I doing wrong?
>> 
>> The RPi boot program doesn't know about plan9 executables. It
>> will just copy the bits from the kernel file specified in
>> config.txt at address 0x8000 and jump there. See 9/bcm/words
>> for some details.
>> 
>> > 2. A couple of my keyboards don't work with the standard kernel on the SD
>> > card (the mouse works fine). Is /sys/src/omap/usbehciomap.c the right place
>> > for me to start looking into adding support for them?
>> 
>> This thread may help:
>> 
>> https://groups.google.com/forum/#!topic/comp.os.plan9/ycok6NTCWCg
>> 
>> Ideally you shouldn't need more than create a custom kbmap file.
>