Using an XP Shower over a vacuum hopper causes an excess of XP to be created when pumped back into tanks using TE fluiducts.

Can't reproduce. Please make sure you are using most recent version and post picture of setup if possible.

Was done in the latest direwolf20 pack

Yup, that's 1.2.7. That's why I asked for version. Already fixed, closing as invalid

http://imgur.com/a/nw1na
This should help you.