Your latest sample looks much better. Once again, it is statistically impossible to compare 5mp images with 9mp images. There are 4,000,000 more pixels present and that in truth, makes it really impossible to compare the two images. This is the apples versus oranges scenario, that we spoke about earlier.
I cannot be 100% positive, but I think that your TZ-5 is just fine. Here is a good photo example of what the TZ-5 can do without flash indoors. I took this photo this morning, while grocery shopping in the nursery department. I used the normal mode, turned the flash off, raised the ISO setting to 800, and added EV +0.3.
The result was a very pleasing photo. Max give your TZ-5 a chance, and I think you will be just fine.