Just thought I'd post that we upgraded to 4.5.6 NE last night from 4.5.5 NE on SuSE ES9 with no issues.
It may be my imagination, but the web UI performance seems noticeably snappier with 4.5.6 over 4.5.5.
And John Holder, I hope you notice I updated my profile as well to include the 4.5.6 information, replacing the 4.5.5 info there previously! :-)
All the best,