To quote the Angry Asian:
"Absolutely DO NOT use a standard "football needle" as stated in the Rock Shox manual. These types of needles have a hole in both the tip and the side. The hole on the side usually has sharp edges that will tear your air valve and create a leak in the system. Be sure to use a needle that has a hole in the tip ONLY."
And yes - i did kill my original top cap seals on my 98 SIDs with a football needle, suitably lubed. If you can find some - replace the top cap with the later SID ones, with the Schraeder valves in. The thread pitch is not the same from memory, but it was what TF used to do when they had stock of the newer top caps. Last time i contacted them i supposedly managed to get the last 2, but they may get hold of 2nd hand ones i guess.