Have you tried something like a Sunsniper strap? Much more comfortable than a standard neck strap.
Sunsniper
.I maybe sound thick but isnt there a kind of bag you can get that will make your life easier?
Hi Brian
Also check out the black rapid, I use one of these and its a neck saver even with a gripped 7D complete with one of my long lenses on..
http://www.warehouseexpress.com/buy-black-rapid-rs-7-camera-strap-with-fastenr-2/p1520232
Mark
Is that with the sigma strap on the tripod foot?
If so, I used the pads off an old lowepro shoulder bag strap on mine when I had the 120-300mm. Made it so much more comfortable
Something like this?
http://www.morrisphoto.co.uk/ProductDetails~man~Billingham~productID~6669~categoryid~163.html
Or maybe a guitar strap pad
http://www.musicroom.com/se/ID_No/0321931/details.html?kbid=1582
Have you got a jessops or jacobs nearby? Might be worth checking if any of their cheap shoulder bags have a pad that you could remove and use on your strap.