According to the post
here the 555 limit in LabVIEW 6.1 is no longer in 7.0 but I don't know if there's a much higher limit or if you limited only by the amount of memory in the computer. How many do you have? By using clusters and arrays, you should be able to dramtically reduce the number. You might also want to think about moving seldom used indicators to subVIs that pop-up on demand.
