IP Address reputation

I have a small problem that could become a big one. I noticed that alot more websites make me do captchas than they used to and I was banned from Home Depot and Lowes websites. So, I checked some reputation sites and while my ip address is not blacklisted there could a reputation problem. I don't fully understand the issue, it involves the DNS reverse ip lookup check.

These checks fail and I look shady like a spamer. I understand little about how ip addresses are used ,but this one is used by other people. This may be ok. One reputation site said my ip address might be a prox server.

  It could be a real big problem in future with email and websites.

Phone calls to tech support do not give me any answers only upsales. Hope someone can help me with problem