file timestamps in a git tree

[Saulius Krasuckas]

I make an ugly hack in a branch at my git tree.  
Then I run after following after some git updates:

$ git rebase master ugly_hack
$ make
Makefile is older than Makefile.in configure, please rerun ./configure
make: *** [Makefile] Error 1

$ git checkout master
$ make
Makefile is older than Makefile.in configure, please rerun ./configure
make: *** [Makefile] Error 1


Is this behaviour intended?  I thought git would reset all the file 
timestamps once I switch to another (master) branch...  Am I wrong?