Unknown index entry format 40000000

Hello,

I've set core.sparseCheckout true and added a .git/info/sparse-checkout file: * !source/crn/ !source/maemo-beagle/ !source/maemo-kernel/ !source/u-boot/

After that, I did git co -- . git reset --hard HEAD

Now, I want to do git pull but I get an error:

beninb:git beni$ git pull -v
From gmuasch:ife-maemo
 = [up to date]      master     -> origin/master
fatal: Unknown index entry format 40000000

I have git version 1.7.0.2, Mac OS X 10.6.2 on HFS+ case-*in*sensitive.

I found that this error comes from read-cache.c, line 1235. What does this error message mean? How can I make my repo working again?

Thanks and Best Regards, Benedikt Köppel