There's lots of questions here, we'll try to tackle them all.
I don't know what this precip is. It seems to be a typical aqueous solution, with just a trace of organic additive, so it should be stable indefinitely. I'm assuming you've prepared it with HPLC grade water and solvent, and you filter the sodium acetate solution after preparation, and you've kept the eluent free of dust.
As for precipitation within the column, that can be a very diverse problem. Sure the same precipitation can happen in the column as happened in the bottle. But maybe you've gotten the precipitation for another reason.
First off, check the the system without the column is clear. You might try replacing the guard column, if you think there's a blockage, it should be there. Thing is, if the method is very aggressive to the column, or the samples are very dirty, a column may only last 300 injections.