wrong data type #VALUE! error

I am using an IF(OR(ISBLANK formula to make some calculations e.g: =IF(OR(ISBLANK(C5),ISBLANK(C$50)),"",((C5/C$50)*100)). In some cells this has been working beautifully and the calculation cell is blank. In others, I get a #VALUE! error that claims that one of the cells in the formula is the wrong data type. This generally happens when there was once a formula in one of the parent cells (in this example, in C5- the result of an earlier ISBLANK formula) but I copied and pasted in the values only. The other parent cell (C$50) also contains a formula but, this doesn't seem to be a problem for other cells.

Does anyone know what is going on...Does it matter that a parent cell used to contain a formula? and how to remedy this error?

I've attached an example file where the formula works in D (one parent cell never contained a formula, the other parent cell still contains a formula) but the error occurs in E (copy and pasted values only in one parent - the result of an earlier ISBLANK formula, other parent still contains a formula). Columns B and C are the parent columns.

Many thanks in advance!

From what I see the formula works fine and where you see #VALUE! this is because C5 is not really blank.

Select C5 and clear that cell. The formula will work fine now. If you don't want to manually clear all those cell, try selecting column C then run the TrimAll macro http://www.mvps.org/dmcritchie/excel/join.htm#trimall

You're most welcome...thanks for the feedback