DdeGetLastError always returns 0

Basically our DdeGetLastError is always returning Zero. Seems it is not able to extract correctly the Error.

Test showing the issue:
http://svn.reactos.org/svn/reactos/trunk/rostests/winetests/user32/dde.c?revision=62533&view=markup#l382

Here we're calling DdeClientTransaction with XTYP_POKE and no item ("0" as hszItem param).

Our DdeClientTransaction handles correctly such situation and sets properly the error:
01157 case XTYP_POKE:
01158 if (!hszItem)
01159 {
01160 pConv->instance->lastError = DMLERR_INVALIDPARAMETER;

However, when we call DdeGetLastError, it doesnt return DMLERR_INVALIDPARAMETER but 0.
http://doxygen.reactos.org/da/d10/dde_8c_acb70a294e0b7492579fa13518e54596e.html#acb70a294e0b7492579fa13518e54596e

dde.c:389: Test failed: Expected DMLERR_INVALIDPARAMETER, got 0
http://svn.reactos.org/svn/reactos/trunk/rostests/winetests/user32/dde.c?revision=62533&view=markup#l389