Sorry,
It's hash.web, and here's the exception (little long) :
(Code generaly work, but it sometimes has this exception).
Thanks

--------------------
Server Error in '/WebApplication1' Application.
--------------------------------------------------------------------------------
Access to the path "C:\WINNT\Microsoft.NET\Framework\v1.1.4322\Temporary
ASP.NET Files\webapplication1\8dd84b00\b065eec7\hash.web" is denied.
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information
about the error and where it originated in the code.
Exception Details: System.UnauthorizedAccessException: Access to the path
"C:\WINNT\Microsoft.NET\Framework\v1.1.4322\Temporary ASP.NET
Files\webapplication1\8dd84b00\b065eec7\hash.web" is denied.
ASP.NET is not authorized to access the requested resource. Consider
granting access rights to the resource to the ASP.NET request identity.
ASP.NET has a base process identity (typically {MACHINE}\ASPNET on IIS 5 or
Network Service on IIS 6) that is used if the application is not
impersonating. If the application is impersonating via <identity
impersonate="true"/>, the identity will be the anonymous user (typically
IUSR_MACHINENAME) or the authenticated request user.
To grant ASP.NET write access to a file, right-click the file in Explorer,
choose "Properties" and select the Security tab. Click "Add" to add the
appropriate user or group. Highlight the ASP.NET account, and check the
boxes for the desired access.
Source Error:
An unhandled exception was generated during the execution of the current web
request. Information regarding the origin and location of the exception can
be identified using the exception stack trace below.
Stack Trace:
[UnauthorizedAccessException: Access to the path
"C:\WINNT\Microsoft.NET\Framework\v1.1.4322\Temporary ASP.NET
Files\webapplication1\8dd84b00\b065eec7\hash.web" is denied.]
System.IO.__Error.WinIOError(Int32 errorCode, String str) +393
System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access,
FileShare share, Int32 bufferSize, Boolean useAsync, String msgPath, Boolean
bFromProxy) +888
System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access,
FileShare share, Int32 bufferSize) +44
System.IO.StreamWriter.CreateFile(String path, Boolean append) +55
System.IO.StreamWriter..ctor(String path, Boolean append, Encoding
encoding, Int32 bufferSize) +49
System.IO.StreamWriter..ctor(String path, Boolean append, Encoding
encoding) +20
System.Web.Compilation.PreservedAssemblyEntry.WritePreservedSpecialFilesCombinedHash(Int64
hash)
System.Web.Compilation.PreservedAssemblyEntry.DoFirstTimeInit(HttpContext
context) +851
System.Web.Compilation.PreservedAssemblyEntry.EnsureFirstTimeInit(HttpContext
context) +97
System.Web.Compilation.PreservedAssemblyEntry.GetPreservedAssemblyEntry(HttpContext
context, String virtualPath, Boolean fApplicationFile) +29
System.Web.UI.TemplateParser.GetParserCacheItemFromPreservedCompilation()
+91
System.Web.UI.TemplateParser.GetParserCacheItemInternal(Boolean
fCreateIfNotFound) +148
System.Web.UI.TemplateParser.GetParserCacheItemWithNewConfigPath() +125
System.Web.UI.TemplateParser.GetParserCacheItem() +88
System.Web.UI.ApplicationFileParser.GetCompiledApplicationType(String
inputFile, HttpContext context, ApplicationFileParser& parser) +171
System.Web.HttpApplicationFactory.CompileApplication(HttpContext context)
+43
System.Web.HttpApplicationFactory.Init(HttpContext context) +485
System.Web.HttpApplicationFactory.GetApplicationInstance(HttpContext
context) +170
System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr) +414