It is not possible to read text values from excel8 files created with fpspreadsheet.
Attached is a modified demo projects.
Run excel8read: the cells with texts are not printed
Now open the test.xsl file with openoffice and do an action to force the save (e.g, resize a column)
Save the file
Run excel8read: all cells content are printed
Using Lazarus 0.9.31 r28168 FPC 2.4.2 i386-win32-win32/win64 (windowsxp)