Media Server :: String Parsing By Remote Java Server?

I am writing a game where positions of an object are being exchanged between the two flash clients through a java server. The secnario goes simply like this:
 
PlayerA ---> Server : "Position X + Position Y+
"
Server ---> PlayerB: "Position X + Position Y+
" 

and it works both ways of course.the problem here is that on my computer where i use "localhost" everything is fine and the data is exchanged seamlessly .. when I loaded the server on a remote host the message received strangely turns into something like "Position X + NaN" (i.e. the y position is wrongly parsed by the server), what is weird even more, is that sometimes, the message gets parsed correctly..the server is wrote in java and it is exactly the same source code that works on my machine that fails over the internet