have you emailed Vlad directly reporting this as a Bug?
It seems odd (to me) that the Syntax "IN NEW WINDOW", "IN CURRENT TAB" (and 1 other, can't remember) use the "IN" keyword,
but when he added "NEW TAB" its not "IN NEW TAB".
Why just NEW TAB if its also
IN CURRENT TAB ?
You only say "won't display" when using "NEW TAB" - but what happens?
A blank Tab? Was there network traffic? What does the developer console show?
Perhaps its a legit bug in that something is expecting the "IN" part in one place in his internal code, and not in the other.