Thanks for the reminder on the market tip, folks. I don't believe it needs to be a 'poison' card specifically, but it does need to be a GHEIST
card that you only have one of in your collection. (If someone knows for certain, I'd love to hear it.) At the point when it "comes back" into your collection, the game searches for any related missions it can unlock.
For anyone who feels their own computer/browser's limitations are the responsibility of UR - Most browsers allow you to INCREASE your cache size. Thus, if you don't wish to reset your own cache as frequently, you may simply devote more memory to it. Again, since I am neither on customer support nor a tech guru, I'd generally refer you to CS if you need help on how to do this.
When anyone, mod or otherwise, suggests you contact CS, it's not just a 'pass the buck' situation. It's quite often a "Hey, if you actually try this, you might find they have a legitimate answer that I simply don't know about" situation. Sure, that requires actual involvement on someone's part, and it's much easier to lay complaints at the feet of others actually putting forth constructive efforts to help, but hey. It's an option. ;-]