dosemu and ubuntu 14

Excuse for my english

With the first installation of Ubuntu 14.04, dosemu work fine (foxpro under
dosemu work fine!)
Linux  3.13.0-27-generic #50-Ubuntu

But now, 10 june 2014, after I've update the system
Linux  3.13.0-29-generic #53-Ubuntu SMP Wed Jun 4 21:00:20 UTC
2014 x86_64 x86_64 x86_64 GNU/Linux

foxpro under dosemu don't work with this error:
"
Phar Lap err 35: The 386 chip is currently executing
in virtual 8086 mode under the control of another program.  You must turn
off this other program in order to use 386|DOS-Extender to run in
protected mode
"

What's the problem?

Thanks

Tom