Most probably it is fixed already. I tested with different cases using '-' and it...
Export to MS Word XML broken/changed in 2.8b2
multiple keywords problem
java.io.IOException
Error regarding length of string
Fixed and merged. Pull request #29 https://github.com/JabRef/jabref/pull/29
Fixed and merged. Pull request #28 https://github.com/JabRef/jabref/pull/28
Printed attribute