Excel 2010 becomes unstable when
Application.MultiThreadedCalculation.Enabled = True and when
Range.Calculate is used in VBA. Sometimes it locks up during the
calculation. Sometimes it crashes upon the next <F9 recalc.
Sometimes it locks up on saving the workbook.

My application employs lots of UDFs, and memory arrays which pass data
from one UDF to another. It works impeccably in Excel 2003 and 2007.

Patch: I set "Application.MultiThreadedCalculation.Enabled = False"
before a "Range.Calculate" and back on afterwards. That seems to
solve the problem.

Does anybody know anything about this?