Rendering very lengthy

[Guest]

Below is the output from a trace of an ASP.Net web page - XLSOutput lines are
trace.writes in my codebehind. The first number is the cumulative time and
the second number is the delta t for the listed operation. The quesion is..
what would cause the status line to flicker the same URl repeatedly and the
render time to be over two seconds? Any suspicious places I should look. I'm
not sure exactly when this started happening , as this is a very large
project with multiple developers. i.e. I'm looking for any pointers in the
right direction! Thanks!

aspx.page Begin Init
aspx.page End Init 0.000060 0.000060
aspx.page Begin LoadViewState 0.000090 0.000029
aspx.page End LoadViewState 0.000189 0.000099
aspx.page Begin ProcessPostData 0.000214 0.000025
aspx.page End ProcessPostData 0.000267 0.000052
aspx.page Begin ProcessPostData Second Try 0.000295 0.000028
aspx.page End ProcessPostData Second Try 0.000318 0.000024
aspx.page Begin Raise ChangedEvents 0.000342 0.000023
aspx.page End Raise ChangedEvents 0.000366 0.000025
aspx.page Begin Raise PostBackEvent 0.000390 0.000023
XLSOutput Filling Cell 1 , 1 0.556095 0.555705
XLSOutput Filling Cell 2 , 1 0.558191 0.002096
XLSOutput Filling Cell 3 , 1 0.560302 0.002110
XLSOutput Filling Cell 4 , 1 0.562396 0.002095
XLSOutput Filling Cell 1 , 2 0.564436 0.002040
XLSOutput Filling Cell 2 , 2 0.567073 0.002636
XLSOutput Filling Cell 3 , 2 0.569376 0.002303
XLSOutput Filling Cell 4 , 2 0.571665 0.002289
aspx.page End Raise PostBackEvent 0.914287 0.342622
aspx.page Begin PreRender 0.914369 0.000082
aspx.page End PreRender 0.914436 0.000067
aspx.page Begin SaveViewState 0.915904 0.001468
aspx.page End SaveViewState 0.916062 0.000158
aspx.page Begin Render 0.916115 0.000053
aspx.page End Render 2.918142 2.002027