New A55 - Question about picture quality

Just got back from my first trip with my new A55. Most of the pics were alright (well, putting aside operator issues). But a few had some issues as in this one. Wondering what causes this, and how I can fix it.

Notice the signs. For example, the "White Room" sign has a lot of blurriness to the lettering. It seems the white from the letters has bled over to the blue of the sign.

Although I'm not new to digital, I am new to digital SLR (I suppose technically I've skipped that with the A55). This was shot using a Minolta 28-80 lens, ISO 100, jpeg.

Wondering what causes this and how to fix it.