I installed irqbalance for fc7. I rebooted and during the boot, it said,
irqbalance [ok]


But when I ran the command
[root@localhost ~]# /sbin/service irqbalance status
irqbalance is stopped
[root@localhost ~]#

??

I thought I might have figured it out but now I am confused. Here is what I did:

[rosatimr@localhost ~]$ su -
Password:
[root@localhost ~]# service irqbalance start
Starting irqbalance: [ OK ]
[root@localhost ~]# chkconfig --level 345 irqbalance on
[root@localhost ~]# /sbin/service irqbalance status
irqbalance is stopped
[root@localhost ~]#

You only have a single CPU system (see your cat /proc/interrupts output) so the irqbalanace service is not needed. I noticed (once again) that your system has three USB ports using the same IRQ;

5: 6057833 XT-PIC-XT uhci_hcd:usb1, uhci_hcd:usb2, uhci_hcd:usb3

What else is attached to these USB ports??? A mouse maybe maybe?? Does your system support acpi (more then IRQ's 0-15) or only apm(only IRQ's 0-15)??? Is the acpid rpm package installed??

I done about all I can do here, I cannot solve this IRQ problem, you have to. Using acpi may work or may not it depends on the motherboard (BIOS settings) and what is installed and configured at boottime. Check and see if you have the acpid rpm package installed, and if yes then why is not being used. If not the system's BIOS settings then maybe the motherboard is a bit to old or the grub.conf file needs tweaking. I can tell you most fairly modern systems do not need an IRQ for the video interface.