Excel 2010 VBA Sheets Copy function works, but then jumps to the beginning of a function

I'm having trouble using the worksheet copy command in a VBA subroutine. I have the following line in my code:

Sheets(copySheetName).Copy Before:=Sheets(beforeSheetName)

When I step through my code and execute this line, the sheet is copied as expected and put in the correct place, but then instead of the next line of code being highlighted, the pointer jumps to the first line of a function (in a different module) in my code.

Does anyone have any thoughts on why this is happening?

Sixthsense,

Thanks for your rapid response - 7 minutes!

I assume when you say ThisWorkbook Module, you mean the ThisWorkbook entry under the Microsoft Excel Objects folder. I checked and there is no code in that object. I also checked the objects associated with all my tabs - no code in any of them.

FOLLOW UP

I just tried an experiment. I made a copy of my file and then deleted all the modules except the one with my Sheet Copy code. The pointer now steps through to the next line as expected. So there must be something wrong with one of the other modules, possibly the one containing the function that is stepped to. I'll do some experimenting.

Sixthsense,

Here is what is happening:

After executing the Sheet Copy code line, the excution jumps to the first line of a user-defined function in another module, in the same project (not in personal.xls). This module contains many user-defined functions that I have created, but most are not called in this workbook.

The function that the execution jumps to IS a function that I call from one of my worksheets. If I delete this function, then the execution jumps to another user-defined function that I call from a worksheet.

Here's the code:

Public Function TMtoLL_VN49(output As String, East As Double, North As Double, dp As Integer) As Variant
'Hardwired WGS84 and UTM Zone 49 N (CM 111 E)
Dim Projection As String, InputEllipsoid As String

Projection = "UTM Zone 49N"
InputEllipsoid = "WGS84"

TMtoLL_VN49 = TMtoLL(Projection, InputEllipsoid, output, East, North, dp)

End Function

It is part of a set of functions that I wrote many years ago to do map projection calculations. I use these functions all the time and they work consistently and reliably, when called from a cell.

I'm going to keep deleting functions until the error goes away.