Very Bizarre "Feature" with new V5R1 CUMET tape and Spacesin Document Name

OK....This one baffles me.

Last week, we applied the latest V5R1 Cume tape and some additional PTFs.  

Right after that we started noticing that when we attempted to open HTML 
documents in a browser (stored on our IFS) and those HTML documents contains 
spaces in the names (i.e.,   TEST DOCUMENT.HTM),  that we were unable to open 
it.  

Further investigation reveals that even from a DOS window, with a mapped 
network drive, attempting to do a DOS copy or rename ALSO fails...unless you 
first enclose the document name in double quotes. 

If we rename the document so that it contains no spaces, then everything works 
fine.

Has anyone seen this problem?  Anyone have any suggestions?

Thanks,

Shannon O'Donnell