Whats up with my line tool? (CS)

Just bought/installed PS CS, and am missing my usual line tool, after hrs of searching I have got no more time, therefor these 3 questions:

- How do I get a smooth default line with my line tool (jagged at the moment)?
- How do I define thickness (in pxl)?
- How do I get rid of the edge kinda of thing that shows untill one draws a new line?

Hope someone can help.

Regards,
Christine

Ok, so far Ive found a solution for the 1st and 3rd question, but the thickness wich is presented as "Weight" at the top bar, is shown in cm - I want it to be pixels. Fx I want a 2 px width on the line - cant do that when the smallest is 0,1 cm.

Ive changed from cm to pixels in preferences, so I do not understand why exactly this is in cm.

Anyone with a solution?

hmmm
never had that problem, and under my preferences its set to points rather then pixels - and my 'weight' is in pxls