Export to XLSX

What exactly is wrong with Excel 2007 export?

Excel message says:
Excel cannot open the file 'test.xlsx' because the file format or file extension is not valid.Verify that the file has not been corrupted and that the file extension matches the format for the file.
if you continue you get a blank file.

using 2003 export it errors also but does give you data.
Tried several project - all seem the same.

They are encrypted but work fine on my other VPS.
Thanks,
Mike.
2003 format displays invalid characters?
eg:

03/02/2003
08-11
As Carer
Learning DisabilityC
Has Downs syndrome, right sided hemiplegia due to stroke, epilepsy
»

ÌÑ
*+‚
€Á

ƒ„&ffffffæ?'ffffffæ?(è?)è?¡"
d


XX333333Ó?333333Ó?
U}

}



} 

} 

} 

} 

} 

} 

} 

}

}

Feel free to post your application to Demo Account and open a ticket at http://support.xlinesoft.com sending your Demo Account URL. 'Demo Account' button can be found on the last screen in the program. Make sure to supply instructions on reproducing this issue on Demo Account.

TY but this wont resolve it. Was hoping someone had had it and found the cause or had ideas on the possible cause..

It works fine on all other servers except this newly built out of the box Centos6 running on a linux os.
I suspect some dependency is either incompatible or has a bug. But I am unsure what is required for this export to function.
Mike.