application working with smart card readers vs RDP and switching users - windows

Question

one windows application works with smart card readers. It has cycle like that:
do{
lErr = SCardListReaders( hContext, ... );
if ( lErr != SCARD_S_SUCCESS )
return 1;
//Show readers
}while(!stop)
i.e. it gets current list of readers, than shows it.
The problem is that this does not work correct with RDP connection. Let's suppose we have computer A (COMP_A) with smart card reader A (READER_A), computer B (COMP_B) with reader B (READER_B). The application is launched on COMP_A and shows READER_A in the list of readers. Then we connect from COMP_B to COMP_A via RDP. Correct result of this must be that there is READER_B in the list. But the application "crashes" because SCardListReaders returns SCARD_E_SERVICE_STOPPED.
Some goggling gave answer that we need to re-establish context. So new version of cycle:
do{
lErr = SCardListReaders( hContext, ... );
if ( lErr == SCARD_E_SERVICE_STOPPED )
{
SCardReleaseContext( hContext );
//Sleep(10000)
SCardEstablishContext( ..., &hContext );
lErr = SCardListReaders( hContext, ... );
}
if ( lErr != SCARD_S_SUCCESS )
return 1;
//Show readers
}while(!stop)
It does not work, SCardListReaders returns READER_A in the list. I suppose because new SCardEstablishContext ends before RDP connection is finally set. At least if Sleep is uncommented it works correct.
The similar situation with user switching, i.e. SCardListReaders returns SCARD_E_SERVICE_STOPPED when user chooses "switch user".
The question is how to make correct code? How to determine that this is RDP connection or user switching? How to re-establish scard context?
Actually i made some changes which use WTSQuerySessionInformation function with WTSClientProtocolType parameter. I wait when WTSClientProtocolType = 2 and then call SCardEstablishContext. But i am not sure this is correct and also it is not correct for switch user.