To expand upon the above answer, Orthodox Answers offers this in response to an inquiry about St. Therese:
"When the Roman Catholic Church canonized Saint Therese, it presented to the faithful an example of a spiritual path to follow. This spiritual path, however, differs from that of Orthodox saints. There are certain beliefs promoted by the Roman Catholic Church as beneficial or mandatory that the Orthodox consider to be erroneous or possibly detrimental to one's salvation. This is why we recognize that Saint Therese is in fact a Roman Catholic saint, but Orthodoxy cannot, obviously, recommend her entire life or belief system as an example for Orthodox Christians to follow. These are Christians that have lived outside the boundary of the Orthodox communion and for which Orthodox bishops cannot make formal proclamations, even if their piety or martyrdom are worthy of respect.
Finally, the reciprocal situation exists: the Roman Catholic Church does not formally recognize Orthodox saints and could not do so for the same reasons explained above." http://www.orthodoxanswers.org/answer/32/
I would add that by not venerating a particular Roman Catholic post schism saint as a Saint of the Orthodox, it does not mean that an Orthodox faithful could not find much to admire about the Christian life, and in many cases, death of a particular saint.
I would recommend that if you are troubled by this or have further questions, meet with your parish priest.