Description:
If a service file depends on a device (starts if, for example some USB device appears), then, when unplugged, this device never disappears. If the device is reconnected, then systemd detects it twice, causes the device rule to fail and the service, depending on this device, to fail with reason "Dependency".

Additional info:
* package version(s)
Good: 219-5
Bad: 219-6

* config and/or log files etc.
* dev-irmp_stm32.device - /dev/irmp_stm32
Loaded: loaded
Active: inactive (dead) since Sat 2015-04-25 18:00:59 CEST; 1min 13s ago
Device: /sys/devices/pci0000:00/0000:00:13.0/usb9/9-1/9-1:1.0/0003:0483:5750.0003/hidraw/hidraw2

Apr 25 18:01:33 manuelspc systemd[1]: Device dev-irmp_stm32.device appeared twice with different sysfs paths /sys/devices/pci0000:00/0000:00:13.0/usb9/9-1/9-1:1.0/0003:0483:5750.0003/hidraw/hidraw2 and /sys/devices/pci0000:00/0000:00:13.0/usb9/9-1/9-1:1.0/0003:0483:5750.0004/hidraw/hidraw2


Steps to reproduce:
This problem, most probably, can't be reproduced on all systems and, of course, needs a service which is meant to start as soon as some USB device is available. I use: https://github.com/VDR4Arch/vdr4arch/tree/master/irmplircd but this requires to have the hardware, too.

If I plug the device for the first time, then everything works well and the daemon starts and works. If I unplug, wait some seconds and replug, then the daemon no longer starts and I get the above error message if I run "systemctl status dev-irmp_stm32.device".