I have just recently had my HDD replaced and the Raw Read Error Rate is high (+60%) and the Seek Error Rate is high (+60%). Why is that?

Values for Raw Read Error Rate and Seek Error Rate are usually high for a new hard drive.

As this is a new drive, it is quite possible that some values may be high. The intent of S.M.A.R.T. technology is to watch a hard drive over an extended period of time (over several weeks or months) to really be able to get an idea if a hard drive presents some problematic symptoms. Only over a period of time, by watching S.M.A.R.T. values, can a concussion may be made about the health of the hard drive and make a prediction of eminent failure.

Here is more information about S.M.A.R.T. and the two attributes:

What is the S.M.A.R.T. attribute? The S.M.A.R.T. attributes are specific properties (parameters) of various parts of a disk. S.M.A.R.T. uses attributes to monitor the disk condition and to analyze its reliability (e.g.: the "Temperature" attribute indicates the temperature of the hard disk, the "Power-On Hours" attribute indicates the count of hours in a power-on state, etc.)

Various manufacturers may use different sets of attributes.

Attribute Name: Raw Read Error Rate Attribute ID: 01 Description: This attribute value depends of read errors, disk surface condition and indicates the rate of hardware read errors that occurred when reading data from a disk surface. Lower values indicate that there is a problem with either disk surface or read/write heads.

Attribute Name: Seek Error Rate Attribute ID: 07 Description: Rate of seek errors of the magnetic heads. If there is a failure in the mechanical positioning system, a servo damage or a thermal widening of the hard disk, seek errors arise. More seek errors indicates a worsening condition of a disk surface and the disk mechanical subsystem. There is no need for concern at the present time if this is a new hard drive.