Thanks Tracy,
I have checked the link but it does not seem to be like my issue.
In my case the report opens up well but on clicking the print icon returns to the parameter prompt without generating any error message.
I have the parameters input and the reportviewer control on the same form.
I have noticed that when the 'Zoom' fails (i.e returns to the parameter prompting page), then on clicing the browsers back button i see that the desired zoom was effected on report.
Another iformation is that for the same Code/Report, the report's print icon does misbehave if i AVOID the ReportDocument but rather load the rpt file directly into the viewer using 'CrystalReportViewer1.ReportSource = Server.MapPath(@"~\Reports\Inventory\CrystalReportTest.rpt");'.
I m forced to use the reportviwer because it allowed me to be able to change the parameter values and rerun without this message:

The report you requested requires further information.
--------------------------------------------------------------------------------
Parameter Field(s)
...

Any ideas?