i went in to the techs tonight cuz i was having a couple little issues. i know in the past, when a problem was happening, it ended up fixing itself after a little bit. i'm trying that with what is going on now. he also said that if there are persistent issues/bugs, htc will release another update to fix those, but it has to run for more than a couple days to see what actually needs to be fixed.
also, he told me to check how long my phone has been on. the longer it is on, the slower/more glitchy it gets. you check this by going to: settings>about phone>battery......up time is the amount it has physically been on. awake time is the amount you have been using the phone, as in not being in lock mode, but actually on it.
he did not know the recommended about for the eris cuz he has the moto. but just turning the phone off and then back on will help a lot.