Links Pages loading in frames/iframes
We have seen quite a few of these lately, and they’re not much better than those previously mentioned. People will load their links pages in frames from sites/domains with no PageRank. An easy way to tell in IE is to right click the area with the links and hit properties. If the address doesn't match that in your address bar of the browser you know it is actually loaded from a different location. While this isn't necessarily a problem, however in most cases these pages aren't indexed in any search engines, hence they are useless.

Link Exchange Beginner Problems.
Sometimes beginning webmaster's make innocent mistakes with their link exchange systems, only because they don't have the proper understanding of how website architecture works. Many people also make the common mistake of misunderstanding how link popularity functions to improve search engine rankings.

If given the proper knowledge, many times a webmaster purposefully develops a link exchange system, which never gives any link value back. In some cases, a redirect is used; in other cases, javascript encoding is used.

Having a solid link exchange campaign is part of your overall marketing strategy, not just as a traffic boost from having a listing on another site, but also from a search engine perspective. It's no secret that many major search engines will boost your rankings not just based on what's on your site, but also what's off it; that is, links from other sites pointing back to you. That is never the case at Zeus, we receive many requests daily for reciprocal links trades and out of 100 such requests, only one or two are worthy of response.