Hi Robbo,
Here's the trick mate, the Switch 142 is the perfect board for you and just luckily happens to be the most versatile board on the market with regard to footstrap positions.
Most people tend to think that the footstraps are right if they are pulling down tight across the top of your foot, this is wrong for most people, especially if your foot is quite wedgy in shape.
As Ian said, there are two sets of inserts for inner and outer footstrap positions on the board and also two holes in the footstrap itself. Try setting the footstrap to the two closest holes on each footstrap ie have the end of each strap close to each other as possible. The idea is to have the strap in tight around the sides of your feet and just snug over the top.
This will keep the strap on your feet easily without having it super tight across the top of your foot. If you have really small feet you can also go to the inside holes on the footstrap itself or use the inside on one end and the outside on the other. This myriad of possibility gives you every conceivable positioning for your feet and I guarantee you will enjoy the feel if you close the straps closer together so it pinches in on the sides of your feet.
Give it a go, you'll be backrolling like a champion in no time.
Also in a few days I hope to have my new website up and running, it has a tips and advice page which for this month will show back rolls amongst other things. Give it a few days and then check www.kiteboardingschool.com.au
Cheers and have a great day, let me know if this worked for you.