Problem with named formula's
 

I have been using named formulas in my spreadsheet. Often, the formulas
don't seem to calculate, or are very delayed in calculating, when one of the
variables changes. Sometimes the only way I can get the name formulas to
calculate is to "toggle" one of values in another cell the formula referes to
by deleting it and re-entering.

Also, the named formulas don't work when I copy them to another cell. I get
"N/A". If I press F2 and enter, the forumula will calculate.

I am using elaborate conditional formulas and are quite complex. However,
the conditional formulas on their own (not named) work fine.

Any suggestions on how to fix/improve this problem?
Thank you