Excel 2008 and 2011 file

I am trying to convert a file from Excel 2008 to Excel 2011. The file is a workbook with 26 sheets in it. I open it up in Excel 2011 and an error message opens and says that it must convert the workbook to a chart table. I accept the change. The problem is all the sheets normally located at the bottom of the workbook are gone. The workbook opens on a sheet and that is the only sheet I can view. Any ideas on how to change it from a chart table work book back to a work book with all 26 sheets at the bottom? I need to inter change between sheets? Each sheet has different data. There probably is an easy fix that I just don't know about.

Is there any way to recover or change it back so I can view all 26 sheets???
Please help thanks

I know this isn't a convert fix, but have you tried to create a new workbook in excel 2011 and then copy and paste the data into it?
Time-consuming I know but if you need it now or soon, might be the best way to go.

- Simon

It may be too late... but did you have the option "always make a backup copy" selected in the 2011 Office preferences? If you did, the original worksheet will be located in your backup folder. If you didn't have that selected (you should) then you will have to use the suggestion that Buzzard offered.

Note: Moved to correct forum.