Hi all,
I'm using excel 2007 with vast amounts of data - file listings of
300,000 files, database dumps that i need to analyze, which have 20
columns and 100,000 rows, etc - and I find that i am crashing excel
pretty often.

Here's what happens, as generally as I can tell:
I open the file (often a .csv or .txt, sometimes a .xls or even
a .xlsx) with over 65,000 rows of data. I begin my calculations,
moving data around, deleting rows, adding columns, and all is fine.

Then i do something from "Actions list A", and excel hangs. This isn't
necessarily the first time I've done that action, and I don't know of
any different circumstances.

Excel will hang for more than an hour if left like this - I've hung it
15 minutes before lunch, gone to lunch, come back, surfed the net, and
it's still hung - and not resolve. When I close excel, I get the
windows "are you sure you want to End task?" dialog, then the "Oh,
excel crashed. Recover data and/or send report?" dialog. Recovering my
file then takes another 15-75 minutes.

"Actions list A" consists of:
Insert a column
Delete a column
Delete the contents of a column
delete a partial row
change a formula, but not the formulas around it
and some others I can't think of.

Is there a fix for this? Anyone know what the problem is? I doubt I'm
running out of RAM or processor: I have an Intel core 2 6600 with
(what windows reports as) 3.25 GB RAM (4 GB).