I haven't yet experienced the same problems of windows bogging up or crashing after closing Xolox. I am wondering if perhaps there are other programs or tasks everyone is using at the same time (I still surf the web & configure some things on PC at same time). There could be many reasons as to why things are bogging up... & perhaps after the program closes, windows is trying to wipe cached memory to allow new info to enter. As we all know this doesn't always work well... so can crash or bogg up the system for some time.
My other guess is that perhaps some other programs/apps being run at the same time are using/sharing the same "dll,winsock,ports,etc..." at the same time & can possibly cause these crashes.
I guess until the coding is made public and we know exactly how they achieve this great program... these problems will remain a mystery.