Small puddle of water on floor by left side of centre stand!?

[Hobgoblin]

Hi all, after a ride of 50 miles or so today, and a good 6 hrs after getting home, I'm in the garage and hear a ' trickle '. There appears a small puddle on the left of the centre stand, which came from an overflow pipe above. It seems to go onto a splitter, then into a plastic box behind the carbs underneath the battery tray area. Is there any reason for this, and is it normal? I changed the coolant last week, but the levels are spot on tonight after the first ride in  about a month.
Can anyone put my mind at rest?!
Thanks, Keith.