The reason is loosely explained in the Bugs section of the animate doc.
config.pdf during DVI to PS conversion and sets the dots-per-inch resolution (DPI) in the intermediate Postscript to the value of
8000. This is equivalent to using
The only benefit of this high resolution is related to fonts generation in case of Type-3 (pixel-) fonts. Nowadays, Type-1 (vector-) fonts are used, which will always make use of the maximum available resolution of the printing device in order to create sharp contours of the glyphs on paper. 8000 dpi were and are just big enough for the commercially available ink-jet and laser printer hardware.
Another side effect of the DPI setting is related to transformation matrix calculation of graphical objects (XObjects) during PS to PDF conversion. (Animation frames and the move-around tooltips are saved as XObjects in the resulting PDF.) Ghostscript's
ps2pdf tends to calculate transformation matrices whose elements have very large values. While these values are numerically correct they are too large for Adobe Reader if the DPI resolution of the intermediate Postscript was set to
-D8000. As a consequence, Adobe Reader displays graphical objects at the wrong position or poorly scaled.
Therefore, it is recommended to either not use
dvips or to override the DPI setting of
config.pdf by running
dvips -Ppdf -D1200 ...
The value of 2636 dpi (
dvips -D2636), seems to be critical here.
Consider the following code example which produces a clickable button in Adobe Reader. The boxed string 'Hello!' is distilled into an XObject and used as the button face:
If the PDF was produced with
dvips -D2636 -->
ps2pdf the button is perfectly visible in Adobe Reader. However, at any higher resolution, e. g.
dvips -D2637 or
dvips -Ppdf, the button face disappears (although the button itself remains functional).