My sister and I own 2 condos that can be best describes as investment rental property. I am being told that due to my and my wife's combined income of over $150,000.00, I am unable to claim/reduce my taxable income the interest etc paid on both mortgages. Additionally, both condos were rented at a "loss" of $1500.00 split evenly between me and my sister. Is it true that the interest being paid on mortgages not associated with a primary resident can not be claimed on an individual's tax return?

If either of these condos was actually 2nd home for you, then you can indeed deduct mortgage interest and property taxes on schedule A. Now, whether that deduction (or your other deductions) actually make it to the bottom line of your return to reduce your taxes depends on the phase-outs for deductions for higher income people, and also whether you are one of the lucky ones caught up in AMT.

However, it sounds like these properties are actually rental properties for you, not a second home. So you report income, expenses, depreciatoin etc on Schedule E, not schedule A of your 1040. See the following for info on reporting rental income and expnses:
Tax Topics - Topic 414 Rental Income and Expenses (http://www.irs.gov/taxtopics/tc414.html)