c# - Why do my breakpoints duplicate in Visual Studio? -

i started having problems breakpoints in visual studio 2010. when set breakpoint , start debugging, breakpoint appears on other line nearby. screenshots below shows editor after set breakpoint, breakpoints window:

as start debugging, breakpoint duplicates, seen in following screenshots:

why happening , how can stop it?

it looks there child breakpoint set up, described in following msdn articles: http://msdn.microsoft.com/en-us/library/b98cwcyw.aspx (link dead, see child breakpoints vs 2010)
http://msdn.microsoft.com/en-us/library/02ckd1z7%28vs.71%29.aspx#vctskbreakpointswindowchildbreakpoints

here similar question on stackoverflow, 1 of answers contains macro remove child breakpoints. perhaps might work you? disable/remove child breakpoints?

alternatively, deleting parent breakpoint (which remove children) , re-creating might resolve problem.