|A: Could be one of several things.
The most likely is what we refer to as the "White Space Problem".
This is due to a lot of extra empty cells being included in the
"used" file area on conversion. It can also cause "Virtual Memory"
or "Out of Memory" problems.
To see whether your problem is being caused by white space, open
one of the workbooks then press the keys "End" + "Home"; this will
take you to the last cell on the current sheet being used by Excel.
If the cell is IV8192, or something very near to it, the chances are
this is the problem you have.
Note: Make a copy of the workbook before you try the solution.
To solve the problem you have to find the last cell in which you
have a value or formula, then highlight all the rows and columns
beyond it and remove any formatting (Edit > Clear > Formats). Do
this for each sheet in the book and then save it. This should solve