I am entering taxes paid against international rental income in the foreign tax credit section, but it isn't giving me a credit

Is the rental income from foreign positive ?  Note foreign tax credit is allowable only based on a ratio of foreign income to world income. 

Also under 26. 904.(j).2.(B) only up to $300 ( $600 for joint filers) of foreign income tax on passive income can be allowed without the limitation , mentioned above.  TubroTax would automatically get you  there  unless you choose to use form 1116 ( for limitation computation ).

Which country? and you are talking about income tax ( i.e. tax on rental income at source ) and not property tax or a tax on the privilege of rental income , based on some criteria other than gross rental income --yes ?