Chucking thoughts about in the hope it may give you a clue.
Had a problem needing to transfer data in usable lumps from a PC to an old Mac Powerbook incapable of further upgrade.
Was able to unplug the floppy port and replace with a serial to USB card/converter.
In the odd way Apple Mac do these things, I could plug all these bits in while the powerbook was running, but big hangups if I didn't back out step by step before shutting down. On the apple it meant dragging any memory stick and the USB connection to the "Trash can" before trying to shut down.
Translated the way I see it - perhaps means forget hot plugging and close ot shut all the tendrils down before you disconnect anything.