iserith
Magic Wordsmith
Look at Jeff's response above. He explains it perfectly. I can technically have the chance of succeeding at something, but I can spend all day trying and not get it. Sometimes it takes stepping away for a while and getting a new approach, or getting new ideas, or looking how other things are done before I can retackle the task and then succeed.
So yeah, the rules cover this. Attempts to achieve the goal via the same approach are only possible if the DM says so. The section I helpfully quoted for you covers this and even discusses (later on) exactly what you want: "But you might decide that the initial failure makes those checks more difficult." Sounds an awful lot like adding 2 to subsequent DCs, doesn't it?
Things are not either totally and always impossible, or automatic success. There's a huge middle ground.
Which is why we call for ability checks sometimes. That's the middle ground between trivial and impossible.
Quite frankly, responses like iserith's are quite unhelpful to the topic because he/she seems to keep insisting there isn't a real problem and I just need to read the book again.
It sounds like it couldn't hurt.