independent scans to same region processed serially

[James Taylor]

Wanted to check with folks and see if they've seen an issue around this 
before digging in deeper. I'm on 0.94.2. If I execute in parallel 
multiple scans to different parts of the same region, they appear to be 
processed serially. It's actually faster from the client side to execute 
a single serial scan than it is to execute multiple parallel scans to 
different segments of the region. I do have region observer coprocessors 
for the table I'm scanning, but my code is not doing any synchronization.

Is there a known limitation in this area? Anyone else see anything similar?
    James