Welcome Mr. DdD, you've to check your drawing's characteristics, is it
a vectorial one? If you use vectorial drawings and you create hotspot using
whole parts (not only the key text), all parts coordinates will be stored in ZXC
file when publishing in PNG format. This should explains your big ZXC file.
My suggestion to manage such as heavy vectorial drawings in PNG format is to
create hotspot using poly-line tool (or other geometrical tool such as circle,
square, etc): you've to create areas around any part you would to become
sensitive, then you've to create an hotspot using this area (not the part)
setting "invisible hotspot" option. Evenctualy you will obtain a drawing with
sensitive area over any part but with a small ZXC file (only hotspotted areas
will be mapped).
For FLASH format you have to use the usual method, ZXC file wont be
affected.
