I created a quite complex query.
To get it easier to read, it spreads on several lines in the sql query editor.
If I try to execute the query, it works fine.

Then I run report wizard. Everything goes fine : all the fields of the query are
detected.

Final step, I finish the report and try to execute it : it crashes and gives me
a msg box containing the whole query and telling me it cannot be executed.

I finnaly found the reason why : if you open the "report source" and go to the
"command" section, the value field contains the query of the report : the query
is converted by the wizard from multi-line (in the sql editor) to single line
WITHOUT adding any space between the formerly existing lines

If you remove what's in the "value" field, then the report works fine.