If you are going to work with custom form which inputs texts to WordPress, this is a must read to prevent headache in near future: WordPress auto-use magic quote for the sake of consistency. Read these link:

  1. [Stackoverflow] With “magic quotes” disabled, why does PHP/Wordpress continue to auto-escape my POST data?
  2. [WordPress Core Trac] The Road to Magic Quotes Sanity
  3. [WordPress Codex] Function Reference/stripslashes deep
  4. [WordPress Codex] Data Validation Approach