Image offset from MouseOver layer, but unsure why

[AEt]

I am quite new to Web Designer Premium and have been experimenting with learning how to create various effects myself, rather than just editing templates.

While attempting to manually create a menu row I have run into an odd problem and I haven't been able to figure out the cause.

When I preview or publish my page, one of my MouseOver objects is showing up in spite of not having been moused over. It is also changing it's dimensions to be longer than it should be.

The object next to has the correct dimensions, however it is pushed out of alignment - yet only if I mouseover from the right side of the object. If I come at it from the left it displays as it should.

The other five MouseOver objects show up as they should, displaying properly and resorting to their MouseOff state when not moused over. They were all created the same way (soft grouped, MouseOff given a web animation for fade - instant) so I can't figure out why these two would be acting up the ways they are.

I have attached an image showing what is occurring. Anyone have an ideas why it might be doing that?