iPhone application to access. / directory file failed

I have two iPhone works. Are written in pure C calls *. A static library. This static library has a function to play log files, access the / directory.

One (Project 1) the creation of normal log.txt file names written content.

Another (Project 2) can not successfully create the file, an error is returned Permission denied, that is, without permission.
I put all the code works 2 copied into a project, delete the original project a code
It is to use a framework to accommodate engineering works two write code. Compilation finished, normal access. / Directory and write files

I carefully examined the two project configurations, did not see what the problem is.

My system is XCode3.2.5 & iPhone SDK 4.2
Using code signing is iPhone Developer, which is the kind of crack the code signature.

Ask the experts, this is what causes.


Reply:
. "/" What? . App directory is not written permission.