Your biggest programming challenge?

[federico_casares]

I'm curious to know... What was the hardest thing you had to do with PHP? What was that piece of code that had you days and days until it worked?

Mine was a group of webservices which had to share information with a lot of servers across different networks to make a login control.

[DeadBattery]

Not too much, just editing some phpBB files for MODs.
;)