Excel 2007 : Deleting Comments reduces number of rows?

[SueWithQuestion]

Can someone explain what is happening in the following?

I have inherited an Excel 2007 file from someone else. I don't know much about how it was developed, except that it started as an Excel 2003 file, the organization upgraded to Excel 2007, and now it is a 2007 file.

When I scrolled down to the end of the file, it was something like 500,000+ rows. However, the data actually ended around row 48,000. I tried and tried to delete the apparent empty rows, but nothing seemed to work.

When I ran the compatibility checker, it complained about something (sorry, I didn't pay enough attention to what the message was). I saved the compatibility report as a worksheet (but later deleted it). In the compatibility report I clicked on the link to the problem cells. I noticed that all of the cells it was complaining about had Comments attached. I deleted all of the Comments. Viola! All of a sudden the file went down to its mere 48,000 rows AND the time it takes to open the file dropped about in half.

What is going on here? What should I be learning from this - other than to beware of using cell Comments?

[DonkeyOte]

If you're saying 48k to 500k cells had comments then that would affect the UsedRange.
Purging the comments and resetting the usedrange would reduce file size accordingly.

[SueWithQuestion]

I should have been clearer. Sorry. No, there were only a total of about 30 - 40 cells that had comments attached to them. When I deleted those 30 - 40 comments, the worksheet went from about 500k rows to 48k, and the time to open the file went from about 6 minutes down to 3 minutes.

What do you think?

[DonkeyOte]

Where were the comments located in terms of range ?

[SueWithQuestion]

My recollection is that they were in 3 different areas of the worksheet: around cell 20, around cell 300, and again around cell 350, and no place else.

[DonkeyOte]

No idea then I'm afraid - I would have assumed you had at least one comment in the last row of the prior used range if purging them reduced the used range.

Someone else may have an explanation for you.