Thanks for reporting the bug, but I'm afraid that we can't easily reproduce it from the info in that message. Also, it's not clear what patches have been applied to the Solaris distribution of GNU tar. So you may have to provide more debugging information.
Some fixes have been made to GNU tar recently in that area, and it's possible the bug has already been fixed. If you have the time and inclination, you can try building from the git repository <http://savannah.gnu.org/git/?group=tar> and see whether that fixes things.
