Never mind, I had a little more time and scooped up this.
This is a copy from the howto install Steam from it's database page on Winehq.org:
download
wine_gecko.cab to the "/tmp" directory and point Wine to it (save this as-is to the "/tmp/file.reg" then import with command 'regedit /tmp/file.reg':
[HKEY_CURRENT_USER\Software\Wine\MSHTML]
"GeckoUrl"="z:\\tmp\\wine_gecko.cab