I am having the same problem. It will randomly happen, not necessarily when I'm typing, and I hardly even use the backslash key. I have to restart the computer to fix the problem. I would like to hear of any possible solution. I have the MBP unibody from 2009.
Hi, just had this problem. Took it to the genius bar and they said they needed to replace the bottom part of the computer. It's going to take about 5 days and $170. Probably happened due to regular wear and tear of the keyboard and trackpad. Or can also happen they said if you spill something on it. Hope this helps.
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