big string in cell create corrupted xls file

```
What steps will reproduce the problem?
1.create a workbook which contains cells with more than 10 000 chars
2. save as compound document .xls

What is the expected output? What do you see instead?
when you try to open it with excel 2007 : corrupted file

What version of the product are you using? On what operating system?
windows.excel 2007

Please provide any additional information below.

```

Original issue reported on code.google.com by `alexandr...@gmail.com` on 3 Sep 2009 at 5:27

Attachments:
- [test.xls](https://storage.googleapis.com/google-code-attachments/excellibrary/issue-46/comment-0/test.xls)

Start by reproducing the issue with the attached test.xls scenario: create cells containing more than 10,000 characters, save as a compound document .xls, and open it in Excel 2007. The work is done when the generated file opens without being reported as corrupted.

Written by the indexing model from the issue text.