I'm using LRT 4.6 on Windows 7 64 bit. My Java and DNG converters are current. I've applied the radial filter to a key frame in the middle of my sequence but for some reason it's ramping backwards to a previous keyframe (in lightroom that keyframe shows the 2 lrt radial filters untouched). Any suggestions? Thanks!

Of course the radial filters are always there - so if you edit one on a keyframe in the middle of the sequence, there will be a transition from the keyframe before (with default settings) and the keyframe after (with default settings too).
So make sure to bring the radial filters that you are going to use to their position at the first keyframe, then leave the settings on zero if you don't need them. Just bring in the settings on later keyframes as you need them.

Ahhhh, I guess this would apply to gradients as well. Thanks Gunther!

Absolutely...