thanks Subah! that worked like a charm
Just a shortcut for anyone reading this thread:
AdminCP -> vbGallery -> Modify Settings
--- Uploading Options
--- Save Original Files (Yes)
Then,
AdminCP -> vbGallery -> Edit Filetypes
Change all dimensions (be sure to keep equal dimensions, ie. 800x800, 600x600, etc.). For explanation as to why see thread Subah linked to above.
Now, to resize all of your current images, while keeping the originals:
AdminCP -> vbGallery -> Maintenance
--- Rebuild Image Sizes (Normal Images)
Voila!