Win 8.1 shuts down when it should sleep or hibernate when Mega2560 plugged in.

My quite new Win 8.1 laptop (with latest OS updates) sleeps and hibernates (not at the same time) perfectly unless my (genuine Arduino) Mega2560 is plugged in, in which case clicking on either the 'sleep' or 'hibernate' icons actually cause the PC to shutdown.
I find sleep and hibernate modes extremely convenient and useful to save power, extend battery life, reduce wear and tear on the machine, and avoid the need to restart applications and reload webpages when resuming work,
but I don't want to have to keep wearing out the USB port socket by plugging or unplugging the Arduino each time I want to suspend or resume work.
Apart from this problem the Arduino IDE and Mega2560 seem to work fine, with no apparent difficulty compiling, downloading, or running programs.
Is an update in the works to fix this bug and is there a workaround in the meantime? Is it still an issue with Win 10? This problem does not occur on my (8 Y.O.) desktop running XP (SP 3 and latest updates) and the same Mega2560.