There is always a pattern with random number generators. Construct uses http://en.wikipedia.org/wiki/Mersenne_twister to generate random numbers so the pattern is quite long and shouldn't be noticeable.
Can you give an example of a noticeable pattern?
Hi, I used the canvas object and pasted objects using random a while ago and the pattern was the same flower shape just looping. I'll see if I can re-create it. I gave only noticed it on certain occations and I'm not sure what is causing it. Some times it seems to work fine.
I have noticed the same thing in MMF a few times.