Hi,

trace your "B"'s memory requirements with

GlobalMemoryStatus
GetProcessMemoryInfo

as well as sys(3050) into a protocol file.
You might add info about "A" as well.
You might also check the swap space possibly
needed for the joins, and required sizes there.

If memory is really sparse when running both
processes, try minimizing process the "A" hWnd,
since that frees up memory OR process all in one app.

HTH

thomas