Hello!
Yesterday I installed bitdefender antivirus 2010 on my laptop vista home 32, and imagine
that the program sketchup 7 pro, lay out, and style builder were frozen several times when initialized - i now the problem it´s something about access to the internet in this programs; those programs starts in a loop; after several hours I understand if i unchecked the real protection /active virus in bit defender, that programs do not freeze more! I went back to my old antivirus. 
Thanks