Right, VST feature doesn't seem to work properly.
I had the same problem, but I copied dlls to WavePad directory and it helped a little. Now, the program isn't blocked but I can't resize the window of effect's panel. I can't also use presets, so this feature is still useless.
I think this is one of most important improvements to be done in the future. By the way: I also suggest the preview of effect or - better - realtime access to effect's parameters.