'_' <-> 0x5f and Jasper

[Keith Wannamaker]

Is there a known problem with jsp filenames containing '_'?
The Jasper in jakarta-tomcat head compiles 'foo_bar.jsp' to
'foo_0005fbar.jsp' for me.  Clearly there is some escaping 
gone awry, but surely I'm not the first to encounter this?
I'm digging into it now...
Keith