asp.net impersonate with windowsidentity

Hi,

I have created a new asp.net website. I use SharpSvn dll to connect in Svn (with url).

Asp.net website use WindowsAuthentication, that is why i use impersonate to use WindowsIdentity to connect Svn with SharpSvn.

When i publish website in my own computer (iis7 windows7), evrything it's allright. but when i publish in server (iis7.5 windows2008 r2 sp1) i have authentication problem.

I don't understand. How configurate iis to run impersonate? Anybody can help me?

Thank's,

Gaël