See Post 8 at:
Script Question posting.
According to Lydell;
"All this is great unless your script is larger than 32KB (PEPV2) or 64KB (PEPV1). If this is the case, then your only option is to use eval() to compile the content of panel labels."
One thing I have done is eliminate all possible white space to reduce the size of the label script. I use
Aptana IDE and it has a selection to compact the javascript. Be careful that some things can't be compacted such as indexes of arrays with an increment in them but these are few in number.