Every time I insert any usb device into my laptop, I get the error from usb 2-1 saying "device not accepting address x, error -62" where x is any number from 1 to 100. before that line, usb 2-1 also logs "new full-speed USB device number x using ohci_hcd"
Both of those lines will be logged indefinitely whenever any usb device is inserted, regardless of distro (tested on fedora 17 live and Mint 13 Cinnamon)
additional info: worked fine until yesterday and i have no idea what the device id of my usb hub is or whether or not it is a built-in motherboard hub or a PCI hub.

I've had something similar in the past, in my case it was down to a dodgy USB port. Since it's only just started, maybe your cable/plug/port is getting a bit worn, or dirty.

Try running rmmod ehci_hcd as root - this disables USB 2, forcing the ports to work as USB 1.1, which is slower but more reliable.

There are more details and suggestions here.

I tried running that command in the terminal as root, and I got this response.
libkmod: ERROR ../libkmod/libkmod-module.c:1791 kmod_module_get_holders: could not open '/sys/module/ehci_hcd/holders': No such file or directory
Error: Module ehci_hcd is in use

Put your error numbers into this command (instead of 62) to see what's going on
Then you can take those errors, and google them with ehci_hcd in the search term. Error 62 is timer expired, btw.

I tried the grep command, and it told me that there was "no such file or directory"

Have you kernel headers installed?
/scratches head

Error 62 is timer expired, anyhow.

maybe I typed in the wrong command, but I got the reply "no such file or directory" I typed in /scratches head

scratches head = joke comment

can you post the output to your /var/log/dmesg pls to a site and link back to it
eg here is mine

http://paste.debian.net/?show=179883;lines=0

I changed mine to hide line numbers and 24 hr expiry but leave yours as is pls

that way we can see if a kernel module is playing up

^playing along.. I don't have a log for dmesg... (might be related to a distro switch to knoppix)

should not be....all previous tests I have done with knoppix have dmesg

ok how about .... /var/log/messages

now it may be huge if you do not have a nice logrotate config so instead try this

insert usb then run command

now that may only show if there is something wrong with your current usb device and not if a kernel module has not loaded

so have a look at

lsmod (and see if uhci* ehci* modules are loaded)

if they are not, I don't have usb3 spec usb device...so name your device spec

then look at increasing the -n (number) to 200 but pipe it thru less so you page up and down

and if you think appropriate post that section showing usb devices being detected here is mine as example
http://paste.debian.net/180394/

good luck