External disk wakes whenever file delete dialog is opened

I've recently dug out an old 1TB exteal drive (USB 2.0) for some temporary storage, it's quite slow (5400 I think) but it's fine for storing unimportant files until I upgrade.

However, every time I delete a file on any drive the delete file dialog pops up and I can hear the old hard drive waking up and starting to spin, as if I've just listed its directory or copied a file there. The entire OS hangs for about 5 seconds while the drive gets going (terminals still run and the clock still ticks, but I can't click any windows, DWM hang?)

It's only a temporary drive, and the wait is only a few seconds (still quite aoying but I can live with it!). I'm just wondering why this happens... could it be related to the Windows recycle bin system? IIRC it stores a bin on every drive/partition but why would deleting a file require reading every drive?

Thanks!