tk - tkenv gui works, then doesn't under windows 7 -

omnet++ v4.6. windows 7 professional.

i have been using supplied omnetpp.cmd \omnetpp-4.6\bin on month success, after few failures (null pointers in omnet) omnet eclipse editor start, when running simulation tkenv window no longer appear. taskbar icon, no window.

when run omnet++ using mingwenv.cmd gives bash shell, omnetpp works expected.

i have rebuilt omnet++ 4.6 environment .zip file again no improvement.

i deleted .tklenvrc file simulation (as suggested in "omnet++ tkenv/gui doesn't appear anymore" question) has no effect. 1 say, "just use bash shell" i'd keep @ windows level. ideas?

i point out recommended way of running omnet++ simulations run them mingwenv.

if have run them command prompt must ensure path contains:

omnetpp_root/bin;omnetpp_root/tools/win32/usr/bin;omnetpp_root/tools/win32/mingw32/bin 

also aware <omnetpp_root>/bin/omnetpp.cmd used start ide while simulations should started mingwenv.cmd bash prompt. these 2 things totally unrelated (i.e. ide , simulations running in tkenv)