it seems that one of solution to fix it is to add:
"padding-bottom: 6px;" into
https://github.com/jenkinsci/jenkins/blob/master/war/src/main/webapp/css/style.css#L412
In this way all tabs have the same height.

Screenshot with fix attached

Fix in pull request https://github.com/jenkinsci/jenkins/pull/1483

@PiotrWielgolaski - Tested your fix and it didnt work for me. I have updated the code @ https://github.com/jenkinsci/jenkins/pull/1544. Please take a look at it.

I have the same problem on 1.596 - Chrome Version 39.0.2171.71 (64-bit)

Is the issue really in progress?

Closed https://github.com/jenkinsci/jenkins/pull/1544.

@PiotrWielgolaski's Pull request should work fine. - https://github.com/jenkinsci/jenkins/pull/1483

Code changed in jenkins
User: Piotr Wielgolaski
Path:
war/src/main/webapp/css/style.css
http://jenkins-ci.org/commit/jenkins/70613202f1177ce83e1d9d724a8b21ca9c222cd3
Log:
JENKINS-25953Tabs in job view are layouted in wrong way

make equal height of tab regardless if selected or not

Code changed in jenkins
User: Daniel Beck
Path:
war/src/main/webapp/css/style.css
http://jenkins-ci.org/commit/jenkins/27dbc6bc588b2a6b44fda7238207994c197a5e2d
Log:
Merge pull request #1483 from pwielgolaski/JENKINS-25953

[FIXED JENKINS-25953]Tabs in job view are layouted in wrong way

Compare: https://github.com/jenkinsci/jenkins/compare/17baaf7151fb...27dbc6bc588b

Integrated in jenkins_main_trunk #3971
JENKINS-25953Tabs in job view are layouted in wrong way (Revision 70613202f1177ce83e1d9d724a8b21ca9c222cd3)

Result = SUCCESS
pwielgolaski : 70613202f1177ce83e1d9d724a8b21ca9c222cd3
Files :

• war/src/main/webapp/css/style.css

Code changed in jenkins
User: Piotr Wielgolaski
Path:
war/src/main/webapp/css/style.css
http://jenkins-ci.org/commit/jenkins/f624aab02251fa7d4d97b05d41954d5dc34575a0
Log:
JENKINS-25953Tabs in job view are layouted in wrong way

make equal height of tab regardless if selected or not

(cherry picked from commit 70613202f1177ce83e1d9d724a8b21ca9c222cd3)

Integrated in jenkins_main_trunk #4292
JENKINS-25953Tabs in job view are layouted in wrong way (Revision f624aab02251fa7d4d97b05d41954d5dc34575a0)

Result = UNSTABLE
ogondza : f624aab02251fa7d4d97b05d41954d5dc34575a0
Files :

• war/src/main/webapp/css/style.css