Can the TA re-agents lose there effectiveness over time? I just opened a new bottle of R0009 (The solution for the last step) and my TA spiked up 20 ppm. I performed the test just as I normally do.

While it is possible for them to go bad, they last quite a long while and several other things normally go bad first.

A difference of 20 isn't all that large. The test is +-10 to begin with. It doesn't take all that much, say a slight difference in dropper tips or slightly different sample sizes, to get it to +-20.

You probably already know this, but the R-0009 sometimes has a bit of static charge so you need to wipe the dropper tip after every few drops. That could easily account for the 20 ppm difference.