Some LEGO elements not attaching as usual I am building a tank made of purely normal LEGO elements, which means no gears or axles or that type of stuff. 

I am trying to attach a 6x6 LEGO plate onto the base for support, but it is not working. I have used pieces from other countries and they all worked fine. The LEGO plate doesn't seem to want to be attached. It is hard to get it to stick, and sometimes a part of that LEGO is sticking out, like it was bent. Do you have any idea why this Lego plate is not being attached as well as others?
Please contact LEGO customer service. They will send you new pieces, and even more importantly, they will make note about the quality issues. The following quote is from the LEGO Ambassador forum in regards to quality issues by Keith Severson, who is the senior manager for community support at LEGO. It is about recent quality problems with another LEGO element (32x32 baseplates), but the same steps apply in your case: 


  "The only way quality and engineering review potential issues is through data that is gathered through customer service. Every time a customer (such as yourself) call in it is logged with the specific element. Once that element receives a certain about of issues they will review it. So the best thing you can do is have your LUG members to report this through the system."


In the USA you can call LEGO Customer Service at 1-800-835-4386 8am - 10pm (EST) Monday - Friday and 10am to 6pm (EST) on Saturday and Sunday. If you are in another country, you can check the official LEGO website for phone number and hours of operation.