Messenger 7.5 audio setup

Hello,

Been having a problem and thought I would describe here in case
someone knows what's up. Googled the problem, but not found. Here goes:

Have messenger setup on XP for girlfriend. She talks to China with it
regularly; however, it seems that each time an audio conversation is
initiated by either side, we have to run through the audio/video setup
process or it will not work.
In other words, we have to perform the audio/video wizzard before each
conversation - it seems as if these settings are wiped out each time.
Anyone know if this is common issue?
Thanks in advance,

.