I put some electrical tape around the rails on my ISM when I used the carbon wing for the same problem. Worked great. No idea what the hole is for.

Sometimes when these rail clips are mounted onto the "elbow" of the saddle they will take a set, and if you then try to mount them to a straight part of the rail, they won't hold the mount properly. Hopefully that makes sense. You would just need new rails clips and if you give me a call I can take care of that. 760-735-3215.
Also the back hole is to mount an X-Nut. We discontinued this part roughly 6 years ago, but glad to see some are still out there!
Damon-XLAB

Damon,

Thanks for the reply!!! I used the other mounting holes on the bend of the rail and its solid now. Also, i found that trisports.com has the X-nut in stock and ordered one. That solved another issue for me.

Thanks again! Matt