I'd check again for a macro.
If you close excel and reopen it in safe mode:
Close excel
windows start button|Run
excel /safe
file|Open yourworkbook.xls
Do you still have the same problem of formulas getting converted to values?
I bet you have some code causing the trouble. It may be in one of the addins
that's loaded if it's not in your workbook.
I'd start looking for "helpful" addins that get loaded when excel starts
normally.
Chip Pearson has some notes on how to diagnose startup errors at:
http://www.cpearson.com/excel/StartupErrors.htm
And Jan Karel Pieterse has more notes at:
http://www.jkp-ads.com/Articles/StartupProblems.asp
===
As for 3.4 showing up 3.99999999999999, excel suffers from rounding errors--just
like any other program that does things in binary.