Hi guys, hope someone can relate :P
The button on my gene berg seems like its lost the tension on the spring that pushes it back to neutral from reverse
I found something similar
http://forums.aussieveedubbers.com/viewtopic.php?tid=69010&page=1#pid644736 
Its hard to explain but hopefully its a common issue
Any ideas?

might just need a service/lube.........pull it out and grease it (moly lube) around the reverse pin and spring at the bottom....

while holding the reverse lock out pin up (at bottom of shifter), you can then wriggle the reverse button out of the handle and clean and polish it too.....then undo the grubs to remove the handle and grease the ball on the end of the cable...don't mess with the cable or try to squirt lube down the shaft, just grease the end where the button picks it up!

take note of which way the base plate goes on the chassis when you take it out and grease the plate well especially where the pin rides.......you can mark where the shifter is "aligned" on the chassis to save any hassles when you put it back in

keep us informed

Hi again
Well funnily enough, i went out today to do exactly what you said and it was working fine!
Weird, it felt so wrong yesterday
Thanks for the help anyway, ill keep this topic in bookmarks in case it happens again