Cannot change scene

This will not be a very helpful bug report but often I cannot cahneg teh scene that I am on.
Normally I will have teh full gambit of scenes in data/predefine but when working on one or 2 I will stripp all teh scenes out of teh directory and want to just play with say 2 or 3 scenes.
Now often I cannot cahnge between them they appear in teh scene selctin box but I cannot chnage to them.
I have been unable to find out why as yet as to actually what situation it occurs buit it does confuse me.
Normally I will have teh full gambit of scenes in data/predefine but when working on one or 2 I will stripp all teh scenes out of teh directory and want to just play with say 2 or 3 scenes.
Now often I cannot cahnge between them they appear in teh scene selctin box but I cannot chnage to them.
I have been unable to find out why as yet as to actually what situation it occurs buit it does confuse me.