I fount a small glitch yesterday , when having the spring verb in preamp position , if you setup a trem before and disengage it, you get a really boosted gainy tone that is really cool, but it last only for 2 or 3 seconds.
It's stange because the spring seems to take away lots of gain to a given amp profile , and that bug sets it back again
Had a similar problem: Loaded the spring reverb in module D and got a volume drop. Also after switching off the spring reverb the volume stays in low level. After loading the profile again volume is back to normal.