Phone conversation - Not getting +5 Randomly

[GayJohnScarritt]

   I've been wondering, why, during phone conversations, when i'm trying to build up daily relationships, i will get a group of only +2 daily (4 or 5 in a row) after the normal +5, switches to +2, then back to +5.  Example, at 40 daily, it starts increasing at +2, then when it hits 50 it'll switch over to +5 again.   Is this just something Maxis throws in to drive me insane?   If yes, is it possible to change it with a hack?   I'm using Autoyak.

[DrBeast]

Probably has to do with topic compatibility. If both Sims are engaged in a high-interest topic you get the +5 REL. If it's high for one but not the other (but still over 5 points) you get +2 REL. If one Sim has a high interest in the topic and below 5 for the other, you get -REL. I've done some research into the matter (though not overly extensive), but still I might be talking out of my ass, heh.

[J. M. Pescado]

I think the critical point for -rel is actually 4 bars, but I'd have to look at the exact value. Basically, interests less than 4 bars mean fingers-in-ears.