OpenVMS: File.read native filepath throws Errno::EACCES: Permission denied

$ sh sym jruby
JRUBY == "$ DKC200:[DYMAX.JRE_503.BIN]JAVA$JAVA.EXE "-Djruby.home=/dym$disk/dymax/jruby-1_3_1" "-Djruby.lib=/dym$disk/dymax/jruby-1_3_1/lib" "-Djruby.script
=jruby" "-Djruby.memory.max=500m" "-Djruby.stack.max=1024k" "-Xmx500m" "-Xss1024k" "-Xbootclasspath/a:/dym$disk/dymax/jruby-1_3_1/lib/bsf.jar:/dym$disk/dymax/j
ruby-1_3_1/lib/jruby.jar" "org.jruby.Main" "-I/dym$disk/dymax/pro/ruby/lib/site_ruby/dylib""

$ jruby -e "p File.read('dsa0:[dm]login.com')"
-e:1: Permission denied - Permission denied - dsa0:[dm]login.com (Errno::EACCES)

Contrast this with the output from a file that simply doesn't exist:

$ jruby -e "p File.read('dsa0:[dm]xy.zzy')"
-e:1: No such file or directory - File not found - dsa0:[dm]xy.zzy (Errno::ENOENT)

But I have no problem using unix syntax here:

$ jruby -e "p File.read('/dsa0/dm/login.com').size"
1925

A reading of the OpenVMS Java doc suggests it may help to define this before invoking my java program to turn on various controls affecting Unix/VMS filepath handling, but it was not helpful:

$ define java$filename_controls -1

Ben