problem with creating rollover states: it" shifts" my images

[liquidaloha]

hi, this is a new problem and i can't figure out what's going on: i'm trying to create rollover states for some images, but when i slice the image that i want to create a rollover for, the image doesn't show up under the web content(but rather it seems like the background color gets sliced instead); what's more, when i click on the "create rollover state" button, my images get "shifted"(even the ones that i haven't sliced), out of the sliced range.
can anyone please help me with this problem?? i've worked on the same computer this whole time and never had this problem before.

thanks!