The following syntax works for me:
[rastername].fieldname * 3
You don't need square brackets around the name of the field, so your should look like this:
[lufumod3].pctimpv * 3
Try that and let me know.
At ArcGIS 10, the Dot Notation does not work in the Raster Calculator. Please see the thread here. There is an enhancement request for this functionality.
Patrick