permission grant set is incompatible between appdomains

HI ,
I have a custom dll that I use to do some of the code expressions across
reports. I have set the required permissions in the rsrvpolicy.config file to
allow it to run under full trust. I have also set the following attributes
on the method in that dll
<System.Security.Permissions.EnvironmentPermission(Security.Permissions.SecurityAction.Assert, Unrestricted:=True),
System.Net.WebPermission(Security.Permissions.SecurityAction.Assert,
Unrestricted:=True)>
Everything was fine till yesterday. Yesterday, my machine was added to be a
member of a domain. I am not getting this error when I try to access the
reports:
rsProcessingError 400 Failed to load expression host assembly. Details:
Assembly mycustom.dll security permission grant set is incompatible between
appdomains.
http://go.microsoft.com/fwlink/?LinkId=20476&EvtSrc=Microsoft.ReportingServices.Diagnostics.Utilities.ErrorStrings.resources.Strings&EvtID=rsProcessingError&ProdName=Microsoft%20SQL%20Server%20Reporting%20Services&ProdVer=8.00
Microsoft SQL Server Reporting Services 8.00.743.00 127 OsIndependent 1033
Microsoft.ReportingServices.Processing Failed to load expression host
assembly. Details: Assembly mycustom.dll security permission grant set is
incompatible between appdomains
Please help!Never mind.
I got some notes by searching in google that fixed this problem. I just had
to restart IIS.
and it starting working
Thanks
George