I noticed when I select multiple rows in jaikoz, if one of the rows is Popularimeter, in the id3 edit tab, it does not delete. It just gives me an hour glass. If I remove this column from being displayed and select a bunch of rows, then I can delete their content without any issues instantly. Seems like there might be an issue with this Popularimeter column not allowing one to select multiple entries and right mouse clicking and choosing delete.
One thing I found odd is when the hour glass is up after trying to delete this column, i can still work within jaikoz. Even do a save which will typically get rid of the hour glass. I have tested this on multiple albums and on a winxp install I have been using for some time as well as a new win7 64bit install and it happens on both.