From: 8os.8 on
recommendation:
revert to the cadimage.dll from 4.23 plugins.
is the last to lack text overlay.
recommendation:
download the zipped package of plugins. do not download the "installer" (.exe) for
plugins.
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background, for anyone interested:
I hadn't updated irfanview since 4.22. 4.25 was (is) current version. I downloaded
the 4.25 plugins exe, and the "after 4.25" plugins that are separately linked at irfan
site.
then noticed some after4.25 .dll had older date than same .dll as installed by the
"all" plugin exe for 4.25. apparently the exe applies install-time date to the dll
(which is annoying, imo)
ahhhthtptht ...

also... I tried viewing some .dwg and noticed:
a nag popup
an overlay of huge "go register this at cadsofttools" (paraphrased)

further checking... conclusion:
the CS_Manager.exe in the cadimage.zip plugin is newly added file. it is the popup
nag. the after4.25 cadimage produces a single large overlay "register at.." text.
the slightly older ver 4.25 cadimage.dll (doesn't include CS_Manager.exe)
produces an array of smaller overlaid "register at.." text.
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but eventually, dwg or other file formats will be "updated", and 4.23 cadimage.dll
will fail to view these.

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cgm.
also maybe useful to somebody: googling and testing, cadimage or another plugin
can read cgm file (i'd never heard of this. it is corel draw file). since i already have
4.23 cadimage.dlll "installed". the text overlay did not indicate whether cadimage
was plugin used to view cgm.

irfanview could see these:
http://lists.oasis-open.org/archives/cgmo-webcgm/200503/cgm00000.cgm
http://nicku.org/snm/lectures/troubleshooting/hub-switch-monitor.cgm
http://www.gwd.org/crew9213/images/venturing1.cgm

other filetype:cgm (by googling) are likely not the same "cgm" format, and irfanview
display is just blank.