Oolite Bulletins

It seems that Sod's Law can be applied to Oolite in that:

"The number of astroids you will stumble across is inversely proportional to the amount of space in your cargo hold."

Or to put it another way: why do I always seem to stumble across bunches of asteroids when I have a full hold but if I have space, I can never seem to find any? Is there a knack to finding asteroids? Are some systems more likely to have them than others? Are there places in systems where I am more likely to find them?

Think it is just random, how many asteroids Oolite adds and where they are. Playing with the piratecoves OXP installed increases their frequency as it always adds asteroids near a pirate cove, at the downside of being attacked by the pirates the cove launches when it spots you.