As you know we use Zoho Sheet as our Online Spreadsheet engine.  There have been some performance and usability issues with larger spreadsheets and anything slightly more "complex".    We recognized this and so does Zoho.   

Zoho has been working hard on resolving all these issues and today has released the following improvements:

New Features:
- Find functionality
- Support for browsers Chrome 4+ and Safari 4+

Enhancements and Bug Fixes
- Huge performance improvements
- Support for large spreadsheets (load 10k+ row spreadsheets in seconds)
- Undo/Redo improvements - Works across all sheets in a workbook. And it is per user basis while in collaboration
- Column level, row level, sheet level styles and formats
- Freeze panes enhancement - images and objects scroll along with the view
- Minimum row height issues fixed
- Insert/Delete columns between merged cells is now possible
- Improved Error reporting
- Row and column mis-alignments have been corrected

If there are any issues please post on this thread or contact support@centraldesktop.com

Thanks,
- The Central Desktop Team