>>As Dragan has pointed out, the objective has NOT been to make plants more pest/disease resistent, but rather to make the plant more PESTICIDE resistent so they could sell more pesticide!
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>The first genetically modified crop I remember hearing about was a kind of rice designed to increase yield. It was being used in parts of Asia to help produce enough rice to feed the population.

Here's an extract from an (undated) article I found:
"GM Rice has only been introduced very recently. In the case of the golden rice strain, pretesting is still being done. Currently, the biggest risk is overlooking something in pretesting, whether it be a direct effect such as toxicity in the rice, or something indirect such as ecological damage to soil organism which rely upon rice for existence. Perhaps the alteration in the rice genome could impact the food web through increased levels of beta-carotene. Furthermore, the genetically engineered rice could negatively impact biodiversity and the potential for disease and pest vulnerability. The risks presented in incomprehensive bio-safety testing are numerous. This one reason that the GM rice should be introduced with great caution. Some evident risks are presented by GM rice though.
Since rice is a staple eaten in large quantities by one third of the world, vitamin A rice could lead to excessive intake of vitamin A. This, of course, is only the case among those who are not at risk of vitamin A deficiency. Excess vitamin A can lead to hypervitaminosis, or vitamin A toxicity. This can lead to nausea, vomiting, dizziness, and bulging fontanelle (gaps between the incompletely formed cranial bones of an infant or fetus).".

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>Tamar