P2 Theme Blog Post CSS Bug

I have installed the P2 Theme 1.4.2 and have noticed that there is a CSS Bug
(at least i think that CSS is the source or Problem).

The Problem is when i click on Blog Post then the whole Text Entry field moves down.

See these screenshots here :

Step 1 : https://docs.google.com/file/d/0B8MBLWqA2dD2TmtialRfNlliS1k/edit
here its ok
Step 2 : https://docs.google.com/file/d/0B8MBLWqA2dD2TW56bFg1M2JlbW8/edit
here you see what happens

This is the case only when i click on “Blog Post”
“Status Update” – “Quote” and “Link” are fine.

In another WordPress Forum Post here i read to add :

overflow: hidden;

to

#postbox {
background: #fff;
position: relative;
padding: 16px 15px 16px 14px;

On line 147 of style.css

which i did and that corrected the problem a little yes but it did not fix the problem.

Anyone knows the solution to this problemo ??

Thank you
-C