Tabs or a special character (an invisible one) most likely copied in from the original paste operation, can have an effect on the way the editor interprets the markup. The edit removed it it seems.
I investigated the first revision and edited it myself. Removing the 4 blank characters and replacing them with normal spaces resolves the problem.
In this case, editing the post to fix the code formatting is indeed the correct course of action. In short, you're not doing anything wrong, just make sure it's 4 actual spaces (ASCII code 32 type spaces) and all will work just fine.
For more specifics, an online ASCII converter detected 4 regular spaces before the actual line of code, but it also detected a NULL value. I also confirmed through trial and error that the very first space, when deleted and re-entered, fixed the formatting; thus, it may not be necessary to replace all 4 spaces in these situations.
Line entered from the actual first revision:
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url
Output from ASCII converter:
NULL 32 32 32 32