That happened to me once with a cider, and again recently, again with cider. The first time it went away, but it took a long time. It was a 1.100 gravity cider which I used Notty for. One packet, since I didn't know anything about pitching proper amounts of yeast. I gave up on it for over a year and when I cracked one recently, the rubbery taste was gone and the cider was awesome.
The newest batch was a test batch which I mashed some maris otter, boiled the wort with nelson sauvin and mixed with AJ. OG was 1.075. After two weeks, the rubbery taste was overwhelming. Two months later, it's going away, but still there. I'm gonna stash this one in the brew closet for awhile, maybe even give it some secondary time. I'm gonna give it a shot in another couple months and see how it's coming along.