Hello Gill,
Not exactly on topic as my reply does not concern the MIOs but when it comes to high BGs after a set change, I noticed this too for a while from time to time. What I do now is as follows and - touch wood - high BGs after a set change are now compatatively rare.
1. I use the same GENERAL area of my body for the cannula sets rather than try and spread them around too much. I think that different areas of the body absorb the insulin at different rates.
2. Change the set immediately before a meal bolus rather than after a meal. That way, you are firing in a good squirt to get things moving rather than a drip drip basal. Banging in more to fill the cannula isn't really the answer as the cannula is of a fixed size and what it says on the tin is what it needs. By sending in more at the "fill cannula" stage, you are effectively giving yourself a small bolus.
Now ... I expect to be shot down as a result of the above but it seems to work for me!
Hope this helps.
Alan