I've been having "issues" with Amp3 for a bit.
Seems to work OK in X3x86 but not in X3x64.
Cake support suggests a re-intall of Amp3; didn't help.
Delete (or rename) the aud.ini file in C:\users\yourname\AppData\Roaming\Cakewalk\Sonar Platinum\
This solved some random dropout issues for me (this was making me CRAZY! Probably explains my occasional "surly" mood here on the forum; sorry for that

).
UFX dropping out at 2048; WTF, over????
Hoping it will "solve" my Amp3 issues as well.
Holding off installing Platinum until I get everything sorted.
Testing later today...
Tom