cant paint over black and white

[Michael Jan E Penserga]

Lately Photoshop's black and white color seems to not mix,

When painting with 100%opa Black and white, painting any Gray on top seems to be impossible, Gray or any other color seems to go behind Black and white, turned opacity down to 90% but still the same thing,

Hope it makes sense, cant paint anything over black and white basically, its as if every other color is on a different layer

This just started to happen when i turned on my comp today. was just painting yesterday without this problem, i don't know whats causing it.

 

[IamSam]

Michael, make sure your brush mode is set to normal.....

 

[OLJensa]

When I hit some strange problem I usually check blend modes first, on tool and layers...