minor annoyance when I use TAB completion

[Fourhundred Thecat <400thecat@gmx.ch>]

Hello,

I have minor annoyance when I use TAB completion in zsh:

When I type "lso" and hit TAB to complete:

  lso<TAB>

the completion successfully completes to "lsof" and my commandline looks
like this:

  lsof <cursor>

notice the one space between lsof and the cursor. But when I start
typing, the space disappears (cursor jumps back), and whatever I typed
is glued to lsof, ie

  lsof| grep

instead of

  lsof | grep

could anybody please advise how to fix this, before it drives me crazy ?
The problem is when I use ctrl+w to delete word backwards, I want to
delete "|" as one word and not "lsof|"

thanks,