Sticking buttons in navigation

HI, Hope someone can direct me on the right path here.
I have a button question that I am dealing with. Sometimes on rollover my buttons are not working properly. I assume it has something to do with the HIT space & how I made the buttons to begin with. I’m just not sure exactly what I need to do to correct the problem. I had worked on this several months ago & thought I had corrected the issue…But obviously I didn’t.
I know you only need one hit space per button…but
I don’t know about blank key frames in the hit space spot…If they are supposed to be there or not?
Since this is sticking rather sporactically depending on where I roll over the button at…I’m at a loss as to what I am doing wrong.

Please could someone point m in the right direction with this?
I’ve looked at it a couple hours & tried several things, none of which seem to be working.

Thanks a lot for all your help.