Finally!
Although some initial case study work done, I have been to and fro with exact ideas for the exact area of research. Finally, today, the supervisor agreed and while I am under no illusions that there is a long road ahead, it is a bit straighter and less deadends!
I can handle having to work part-time to fund meself and the new commute (moving into my own gaff is without doubt the best thing in a long, long while), but that was without doubt, the biggest of the troop of monkeys on the back.
Just thought I'd share one of the better moments and for people stuck in ruts, remember the words of Josh Bilings
Consider the postage stamp: its usefulness consists in the ability to stick to one thing till it gets there.

Thats fab Bonzo!  Do you have those illusive questions defined as well or is that another long and weary road? I thought I had mine wrapped up, but my question werent quite there, they need a bit of reconstructing (according to my supervisor); I've got a bit fed up with working on my final proposal as it feels like I've spent a long time and havent got much to show for it, so I'm working on my lit review for a while and will go back to redefine my questions when I get fed up with the lit review - oh hum!!

Java - yeah, there is that aspect, but hoping to sort that out this week. There would seem to be a Sea Change of attitude from the supervisor so just gonna define it exactly. I am looking at the use of OSS by SMEs for collaboration and there are various cross-threads so gonna pick two-three and stick with them. The technical aspects are a bit daunting but got a good crew for that where I "work".
As regards your own situation, I had to do the same thing i.e. even though I had still to define the idea, I couldn't just leave the other bits. Don't worry - it will come together. It was actually Thursday, when I picked up a book by a leading author in the field and in three paragraphs, there was an encapsulation of the idea. I typed it into the current document (an outline), highlighting the main parts. Keep on trucking and you will get there. Impose a deadline though and don't read too much more - you know your stuff!