.
This is a J1.6/J1.7 bug which has not been fixed.
See:
[#26439] Editors have problems with quotes in content plugins syntax
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_id=8103&tracker_item_id=26439
[#26436] The Plugin Manager still corrupts strings
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_id=8103&tracker_item_id=26436
This bug affects any plug-in which uses the
param="value" structure in the tag.
A suggested workaround is to add a space after the last pair.
Change this
{aridoc engine="google" width="650" height="475"}documents/cng.xls{/aridoc}
to
{aridoc engine="google" width="650" height="475" }documents/cng.xls{/aridoc}
Have not tested this workaround with this plug-in, but it has worked with some other plug-ins.
Perhaps if more users post their problems in the tracker threads linked above this will increase the pressure to get this bug fixed
.