Visual Studio 2010 WebServer Very Slow loading

I'm working on ASP.NET MVC2 project. everything was OK in the last months, today suddenly, the time to load the first page raised from 5 seconds to 1:30 min !

I check the output view and I see many lines like this one:

WebDev.WebServer40.EXE' (Managed (v4.0.30319)): 
Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Runtime.DurableInstancing\v4.0_4.0.0.0__31bf3856ad364e35\System.Runtim开发者_开发问答e.DurableInstancing.dll', 
Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.

some of them are totally irrelevant to my project like this one:

'WebDev.WebServer40.EXE' (Managed (v4.0.30319)): 
Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_32\System.Data.OracleClient\v4.0_4.0.0.0__b77a5c561934e089\System.Data.OracleClient.dll', 
Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.

What happened ? I've tried to change in option not to load symbols, doesn't help, moved to release, same thing.

Any ideas what happened to my development environment ? This is a Win7 X64 machine, VS2010 SP1.

Deleting all breakpoints solved this issue !