Unfortunately since the sldieshow integration, imagevue hasn't been very friendly to integrate into custom flash sites
In your slidehsowimagevueconfig.ini, try setting "boxstage = 700,500" - Just curious if that has any effect. Generally speaking, for Imagevue to integrate optimally, you should be using the followin settings in your main fla else they often don't mix too well together:
Stage.scaleMode = "noScale"
Stage.align = "TL"
Anyway, if the gallery still jumps out of position, you could of course disable the slideshow module and view images in the old fshioned way. In your config.ini, change:
into