I am writing an automation add-in in Office 2007 that implements a number of
user defined functions that use a remote service to retrieve data.

When these functions are first entered, and when a workbook that contains
them is first opened, they evaluate correctly. Once evaluated however I do
not seem to be able to force a re-evaluation. The Calculate Now and Calculate
Sheet options have no effect.

Is there any way to flag all udf's for re-evaluation?