CUPS: "Unable to open USB device" after turning it off

[romee]

I have two printers on 2.6.11-hardened-r15 gentoo server. Both of them work fine, windows clients print via samba shares. The problem is, that if someone turns off the printer, it won't print. I have these messages both in logs and in CUPS' web interface:

[keyson]

Hi.

I hade the same when i was using the cups and the hpijs driver.
Now i use the hplip with cups and it starts the printer up when i
send a printout.

I use a deskjet 970 on usb.