Not Desired Presentation for XLS files with Jasper/IReport

[dr_pompeii]

Dear Members

i used to work with jasper/ireport report and i am fine
usually i generate pdf reports with many pages

i noticed that if in the IReport JasperViewer
i save the preview with extension .pdf, well i get this file

the problem is when i save this to XLS format
i have 2 choices, single/multiple sheets

if i choice single sheets,
well the file is created but cant be open in windows and even linux (open office)

i must choice multiple sheets, but each page from the
IReport JasperViewer generate a sheet in the XLS file
why?

even worst, pls see the attachment file
why the ugly presentation of rows and columns??

normally i work with spring framework
i generate for my application in this way the pdf report

somenamejasperreport.(class) = org.springframework.web.servlet.view.jasperreports.JasperReportsPdfView
somenamejasperreport.reportDataKey = datasource
somenamejasperreport.url = /WEB-INF/reports/xspring.jasper

of course that for XLS report should be

somenamejasperreport.(class) = org.springframework.web.servlet.view.jasperreports.JasperReportsXlsView
somenamejasperreport.reportDataKey = datasource
somenamejasperreport.url = /WEB-INF/reports/xspring.jasper

but the results are the same

can i fix this?, how?

thanks in advanced