Are you typing "buydebug" in buy mode? These are the directions I got from googling:
If not already done, do 'testingcheatsenabled true' in live mode, then go to 'buy' mode, use 'buydebug on'. Then go to the buy mode that has types grouped together (ie surfaces, lighting, etc), look for the question mark bottom right corner, click.
Comes from the official forum, so no guarantees about accuracy. I've never used the cheat since I thought AM enabled it.
ETA: Never mind, looks like the problem got solved.