Created attachment 151071 [details]
material for replicating bug.. instructions in text

I have two sheets, Expenses and PayMethods (listing 6 payment methods: cash, debit, FSF Visa, MC, Discover, Citi Visa).

For the Method column in the Expenses sheet, I set validation to allow 'In a list'.  I select the source "PayMethods!$A$1:$A$6" by using the GUI button.  However, if I just click the "Select source" button, switch sheets, select the range, then click the button again to get back to the Validation dialog and click OK, it sets the validation for the active cell on the PayMethods sheet.

If I manually click back on my original sheet (Expenses) after returning to the Validation dialog (before clicking OK to finalize validation changes) the dropdown menu shows up in the active cells on the original sheet.

INSTRUCTIONS FOR ATTACHMENT:
In Expenses sheet, select D2:D24.  Right click, Format Cells, Validation Tab.
Allow 'In a list'
Source: Click selection tool button.  Move to PayMethods sheet, select A1:A8.
Click selection button again to return to Format Cells dialog.
****
Click OK.

Validation will have been set to the active cell(s) in PayMethods sheet (A3 for me) instead of the cells D2:D24 in Expenses sheet.

Repeat process, but where asterisks are, click the Expenses.txt sheet tab (may have to move Format Cells dialog to reach) before clicking OK in the dialog.