iPod Touch touchscreen malfunction: How I resolved.

I've been using an iPod Touch 3G for exactly two years and it's worked very well with essentially no issues during this time.
However, in the last two weeks or so, I've noticed that the touchscreen was becoming unresponsive on the right hand side and, at times, at the bottom of the screen too.
Hmmm.......does this mean I'll have to splash out on a replacement machine?
Well, let's see if we can resolve it first.
Here's what Apple recommends in this situation. As a first step, clean the screen which seems fairly obvious.
I tried this and, indeed, it did initially seem to have fixed the problem. But, next day, it was back and, if anything, worse.
Indeed, I had great difficulty in even entering my passcode, sliding the poweroff slider or entering any typed information. This was getting really serious.
This is another Apple document which refers to various problems of which touchscreen unresponsiveness is just one.
I decided that perhaps I must turn to a restore as a last resort.
However, when I hooked up to iTunes on my Mac, I noticed that my 32GB machine was completely full. Indeed, iTunes said it was 1.38GB over capacity.
This is not an unknown phenomenon, unlikely as it seems.
Seems I synced it without unchecking a lot of movies that I had put onto my iPad.
OK, so I re-synced my iTouch and got 12 GB free space.
Next, reboot and problem completely gone.
Well, that was easy although I honestly wouldn't have been too disappointed if I had had to replace it with the iTouch 4G with its cameras and inbuilt microphone.