DirectoryServicesCOMException 80072020 From IIS 7.5 Site Running Under ApplicationPoolIdentity

I'm having trouble hunting down an issue where an ASP.NET 4 application fails while trying to get user groups for a given user from time to time. The application pool associated with this application is setup to run under ApplicationPoolIdentity. Exception Info ``` System.DirectoryServices.DirectoryServicesCOMException HRESULT: 80072020 Message: An operations error occurred. Extended Message: 000004DC: LdapErr: DSID-0C0906E8, comment: In order to perform this operation a successful bind must be completed on the connection., data 0, v1db1 ``` Stack Trace ``` System.DirectoryServices.DirectoryEntry.Bind(Boolean) System.DirectoryServices.DirectoryEntry.Bind() System.DirectoryServices.DirectoryEntry.get_AdsObject() System.DirectoryServices.DirectorySearcher.FindAll(Boolean) System.DirectoryServices.DirectorySearcher.FindOne() ``` 95%-99% of the time, this function works fine, but from time to time, it just starts failing. When I change the application pool to use LocalSystem or NetworkService, it starts working. When I change back to ApplicationPoolIdentity it begins failing again. The only way to get the site working again with ApplicationPoolIdentity is to reboot the server. I was able to find a similar issue here, but the resolution was a reboot as well. I'd like to find a more permanent solution short of changing the identity of the application pool.