I don't have an answer for you--I had the same problem. I didn't have an original Swanke one, I had the Playtex brand, but the shoulder strap was a real problem for me. I just couldn't get it right--the pad slid, it dug into my shoulder, etc. Also, by the time I got it my DD was 1 1/2 and almost 30 pounds, so it was really uncomfortable. I went back to using the ring sling, although I don't sling her much anymore as she likes to walk. I have to admit I gave up and gave the Hip Hammock to my sister--her baby is smaller and always preferred the Bjorn to the sling anyway, so thought that style of carrier would suit them better than it apparently suited us. I'm glad your baby likes it--maybe someone else here has an idea. Good luck!
I got my swanke on ebay too (I even wrote to Nancy Swanke to ask about the playtex recall and she answered me immediately that they were all made by hand with double stitch or somehting like that- pretty cool) anyways, I had the same thing with the strap and never got around it, I am just careful to check the strap and pad each time. FYI if you are still baby-wearing next spring - summer, I also bought a hip carrier from One Step Ahead - it is a thin black nylon one and I really love that one too - my swanke is really thick and warm, so it was the fall-winter carrier, and the onestepahead is my spring -summer one.
congratulations on the great buy!doreen
also I had found nancy swankes email addy on some website - i think it was the hiphammock.com or something like that - you can find it if you search a bit maybe google her name - she seemed really nice and quick to answer, so maybe she has some insight on the strap question
Tomâ€™s Wife and Chuckiesâ€™ Mom