Mike,
Try Sir Charles suggestion first. The site may have just been assembled incorrectly?? I don't honestly know.
It does look to me as if the site post was installed on the base backwards?
If this doesn't work out for you...
Please contact me through my e-mail address listed in my profile.
Send me the photo you posted here as well as a photo of the sight on the gun, I will pass that info on to my contacts at DP (along with your e-mail and mailing address). The folks at DP will be back in touch with you.
Best I can offer you at this time.
My best,
Blair