Not in a relationship sense per se, but my experiences with ENTPs lead me to believe that they often don't want to delve into the personal side of things unless it's in the form of them venting. That's perfectly acceptable, but it's so contrary to my own mode of operation that it can be a bit strange--it can feel like it's a problem in getting to know them.
In reality, it's me taking a wrong approach in attempting to get to know them. Or, it's an incompatibility. In any case, I shouldn't expect them to be any different than they are.