I had the same problem with an IPA that I did this summer. Basement was cool, but I pitched extra yeast to account for the higher gravity of the brew. I pitched using a pitching calculator and used Notty as the yeast. Forgot that Notty tops out at 70 degrees. Very strong and fast fermentation and it was left to condition for 4 weeks or so. I bottled and gave it 3 more weeks. Still had the strong rubbery taste. I think that the temp in the fermenter was much higher than the ambient temp of the basement and this was definitely higher than the recommended temp for Notty. Bottled it on August 3 and, upon tasting another bottle a couple of days ago, the taste was still there. Had to pour that one out. I hope that it mellows over the next couple of months, or I'm going to have to toss the whole batch, as I'm very sensitive to tastes and it's too strong of a rubber flavor for me.
While the weather is cool, but not yet cold, I'm switching to US-05 and S-04, which both have fermentation tolerance to 75 degrees. Brewing a pretty high-gravity RIS this weekend, so I hope that this solves the problem, as the basement is now steady around 68 degrees. I use dry yeast almost exclusively as, with a toddler in the house, I'm not always sure when my brewing plans will come to fruition.
So, maybe switching to a yeast with a higher temperature tolerance will help solve your problem.
Jeff