Hi toolfan2k4 ,
I am curious to find if you still have this problem or found a workaround.
I also have a Ubuntu 12. 04 and also a Windows XP host machine. The problem in my case is that when I run my Ubuntu machine I loose keyboard and mouse in the Windows XP machine. If I suspend or shutdown Ubuntu the keyboard and mouse are now OK in Windows XP.
I have a feeling the problems are similar and if you got any info about improving this situation I would appreciate sharing.
Cheers
Serge L.