Well I've never used Nero to edit images but if you uploaded these without any post processing then that may be the reason why they came out a little flat. And also camera sensors usually don't do much of a good job perceiving the differences between light and dark so sunrises and sunsets are pretty difficult to capture without post processing or a whole set of filters.
I used Camera Raw to knock back the exposure a bit, up the saturation, add a bit more contrast and sharpen the silhouette.
All of which can be done easily enough with free software like
Picasa and
Gimp.
PM me or drop me a line on AIM if you want more info.