Thank you for your post.
Another forum customer ran into this issue last year.
Neither myself nor our Testing department was able to reproduce the issue, but perhaps some of the information in that link may help provide a key to your experience.
There was a note from Testing that there was a similar issue reported in 2009, but this was fixed in Mac OS X 10.7.
I have attached your post to the original report. If any further information becomes available, I will let you know.
Thanks TSGal. I'm glad to know I'm not alone!
If I notice this again or have any other observations, I'll make them on that thread.