gnome workstation installation 6.1 e conf diff from default: mouse pointer focus, edge flip disabled, tools tips off, brushed metal theme. make a window sticky, iconify (hide) it, change workspaces and uniconify (show) it.... where's the window? the tasklist button is still present - and it's icon seems to imply that it's not hidden - if you work at it (not sure of the pattern here) you might recover the window through the tasklist and showing/hiding the window through the task button.
This behaviour is still present in enlightenment-0.16.4-5 (Pinstripe Public Beta)
Enlightenment current devlopment is in 0.17.