WPF : Cannot connect to directory

I have a WPF app connecting to Active Directory for authent开发者_StackOverflow社区ication. Its working fine on some computers it doesn't work on some computers.

The environment is Windows XP with .Net 4.0 Client Profile & Extended installed. I've researched all over the internet & couldn't find an answer that's related to the error that I'm getting.

The exception that I get for the users that can't connect to AD is:

System.DirectoryServices.DirectoryServicesCOMException (0x00005011): Unknown error (0x5011)

at System.DirectoryServices.SearchResultCollection.ResultsEnumerator.MoveNext()

at System.DirectoryServices.AccountManagement.ADDNLinkedAttrSet.GetNextSearchResult()

at System.DirectoryServices.AccountManagement.ADDNLinkedAttrSet.MoveNextMemberSearcher()

at System.DirectoryServices.AccountManagement.ADDNLinkedAttrSet.MoveNext()

at System.DirectoryServices.AccountManagement.ADDNConstraintLinkedAttrSet.MoveNext()

at System.DirectoryServices.AccountManagement.FindResultEnumerator1.MoveNext()

at System.DirectoryServices.AccountManagement.FindResultEnumerator1.System.Collections.IEnumerator.MoveNext()

Any help would be appreciated. Thank you.

Thanks Philipp.. there is no more details that the exception throws.. The weird part is, not all end user computers throw the error.. Then striking out all the possibilities.. I found that there was a conflict with the versions of .net that is installed in the client computers. They had all the flavors pf .Net FW. I started removing one by one & left .net 4 which is used by my software & that did the trick. Then I had to narrow it down to .net 1.1 which was the issue.. removing that fixed the issue..