Hi,
Yes, the pngfilt.dll file is a component that helps display images, so it is a trade off. To avoid the error, the workaround would require you to give up image display in some applications.
If you need to get it resolved, and if you can confirm other specific apps that have a similar issue when displaying images (IE, Word, etc.), I think you will either need to open a Server 2008 support case with Microsoft (probably not a Dynamics support case), or try to reinstall Server 2008 R2.
It could be as simple as a version issue with that particular DLL, in which case MS may be able to resolve it, or I suppose it could be a combination of multiple files and registry entries, in which case rebuilding the server may be easier.
Thanks,
Steve Endow
Dynamics GP Certified Trainer
Dynamics GP Certified Professional