CorelDRAW X5 :: Transparent PNG File Export - Settings To Reduce Bloated Filesize

I'm working with a production house to generate transparent PNG files of pieces of content. These output images must meet a fixed height and width (in pixels). We're providing a MS Word file with a template that has both text and a MathType equation. The vendor uses this as a starting point, and will export the same equation as a transparent PNG file.

The vendor is using CorelDraw to: transfer text and MathType equations out of a Microsoft Word document into a template in a CDR file select and export the resulting component(s) as a transparent PNG file

FONT MISMATCH: We have a reference PNG file that we've generated as pixel map directly from an XML version of a piece of sample content. We've found that the vendor's sample PNG file is much larger in filesize than the reference PNG file, though it has the same dimensions.

I'm wondering if it is related to a settings issue in CorelDraw due to a weird font size mismatch. Viewing our reference PNG on-screen on my MacBook Pro (OS X Lion), the font matches 26pt in my text editor at 100% view, which is the same font size we use in our source Word document. The vendor (using a PC overseas) has to shrink the font size after transfer into CorelDraw to 6.2pt font, which visually matches our reference on my screen.

TECHNICAL DETAILS: I've used the "identify -verbose" command in ImageMagick to isolate a few other key differences between our source PNG file and the vendor's sample PNG file. In addition a significantly larger number of rows of Histogram information (source=65 rows; vendor=256 rows), there are a handful of other discrepancies (in bold):

Source PixelMap PNG

Resolution: 72x72

Print size: 6.94444x3.31944
Units: Undefined
Channel statistics:
  Gray:
    min: 0 (0)
[code]...

I've attached a text file with the ImageMagick details for each PNG file. changes to the CorelDraw settings or process to better align the output file with the source. I'm also open to exporting the selected component(s) in a different format (e.g., EPS or TIF) and then converting to PNG with another utility.