file upload allowing wrong formats?

[eluser]LeonardoGaiero[/eluser]
greetings, i'm having a bit of a problem: i'm developing a file upload mechanism for a customer, and it needs to allow a specific subset of files.

i got up to the point of specifying the mime types for the desired formats, but then i encountered a problem in which the application is accepting files seemingly at random. here are my allowed extensions:

Code:

define('ALLOWED_TYPES', 'doc|docx|xlsx|pptm|xlsm|docm|pptx|accdb|xls|pdf|txt|zip|rtf|ppt|jpg|accdb|');

here's the weird thing: no matter what i define as the allowed filetypes, the app will upload them seemingly on its own, and at one point it was even loading exe files. what am i doing wrong, are my configuration settings being ignored? i'm stumped at this point, any help would be much appreciated.