SL3 Drag and drop performance in LMS

Thought I would post this result I have experienced, either in hope someone may be able to explain or simply to note for others. 

I have a drag and drop slide in a SL3 project, with five drag items set to bounce back if they aren't dropped on correct drop targets.  Drag items are simply text boxes, though three of them have various states that are triggered based user selection on an earlier housekeeping slide (for staff to select the service where they work). 

This all works well, except for a very specific situation.  When this file is published for LMS for Flash with HTML5 fall back, and only when viewed in client's LMS, in a browser with Flash installed - the drag items aren't excepted and continuously bounce back.  

From testing it appears that everything works fine in other situations - ie in Scrom cloud, through client's LMS in browser without flash, in the version HTML5 with Flash fb (unfortunately client finds this version quite sluggish on many of their computers).  

My fix is that I am going to redesign this slide so not a drag and drop, though I do like as is so if anyone can see the error please let me know. 

For anyone interested I have attached a summarised version of the working file, (Note: you have to do the housekeeping: select your service slide each time before the drag and drop, otherwise the customised text boxes won't recognise the correct answer)

Thanks all, Christine