i lst with mine, basically what lst does is pulls the plant in the direction you want it to grow, basically i pulled the top of my plant right down and ran it out side ways, this forced all the growth at the nodes to start growing like crazy, what this then does is give you many main tops instead of just the one, but as your not doing that then you could tie the stem to stop it bending any further that it all ready is, i wouldnt say its a problem and as you have no light source at the sides then its not growing towards the light, it looks as if the plant isnt directly under the bulb and when it was younger the plant started leaning towards the light and now its got bigger and covers more area its started growing upwards again, its either that or the root growth is pushing the stem and tipping it over, it dont look like it will have any bad affects on the plant so i wouldnt worry to much, but you could tie something round it and stop it bending more, or turn the pot 180 deg and see if the plant starts getting straiter, or turn it and move it further away from the light so it turns the other way, i dont think you will have any problems if you just leave it, the stem looks thick and strong enough to be able to cope with any weight the buds will put on it so its nothing to worry about i dont think