Sorry, you've stumped me. I copy and pasted the code you posted into a couple of button click-event handlers, changed the prints to a msgbox and I'm not having any problems.
<font face=Courier New><SPAN style="color:#00007F">Private</SPAN> <SPAN style="color:#00007F">Sub</SPAN> CommandButton1_Click()
<SPAN style="color:#00007F">If</SPAN> ListBox1.Selected(7) <SPAN style="color:#00007F">Then</SPAN> <SPAN style="color:#00007F">GoTo</SPAN> errhandler7
ListBox1.Selected(7) = <SPAN style="color:#00007F">False</SPAN>
<SPAN style="color:#00007F">Exit</SPAN> <SPAN style="color:#00007F">Sub</SPAN>
errhandler7:
MsgBox "Lo 7"
<SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">Sub</SPAN>
<SPAN style="color:#00007F">Private</SPAN> <SPAN style="color:#00007F">Sub</SPAN> CommandButton2_Click()
<SPAN style="color:#00007F">If</SPAN> ListBox1.Selected(7) <SPAN style="color:#00007F">Then</SPAN> <SPAN style="color:#00007F">GoTo</SPAN> errhandler7
ListBox1.Selected(7) = <SPAN style="color:#00007F">False</SPAN>
<SPAN style="color:#00007F">Exit</SPAN> <SPAN style="color:#00007F">Sub</SPAN>
errhandler7:
MsgBox "Hi 7"
<SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">Sub</SPAN></FONT>
And button1 one had its TakeFocusOnClick set to TRUE while button2 had it set to FALSE, so that isn't an issue. Sorry wasn't more help. I still suspect a cut and paste or similar error (I've copied more code, knowing I needed to fix a bit here and there and then forgotten to do it...)
Good luck,