Hopefully someone can help!

I've been running various routines in workbooks using vb
scripts...successfully for the past 5 yrs. Just upgraded to 2010 and
various bits of code are now struggling. Admittedly my code could do
with tidying up but it's generally a bit of a head-ache.

One thingthat throws a vb script error is if the following line is
included in any of my workbook macros:

Application.VBE.MainWindow.Visible = False

.....anybody know why this is happening as it wasn't a problem in 2007?

Any help much appreciated,
J