Unable to interrupt through gdbserver

I have been trying to remotely debug my embedded program using QtCreator 
and GDB but have been having trouble.  I took QtCreator out of the loop 
to try to isolate the problem and have gotten to the following.  While I 
am able to interrupt the embedded program via `kill -INT <PID>` (or 
-TRAP) I am not able to interrupt it in GDB using either ctrl-c while 
not at the prompt nor via `interrupt` when at the prompt.  Ctrl-c twice 
will return me to the prompt with a `Quit` message but does not 
interrupt the process.  I am running a locally built cross-debugger 
suite with GDB and gdbserver from 7.9 with Linux on both the desktop and 
a PowerPC embedded target.

The application is being launched on the embedded Linux target and 
subsequently I run `gdbserver --attach :10000 <pid> &` on the target.  I 
then launch gdb on my desktop and run the following:

set sysroot /local/sysroot
file <desktop path to executable>
target remote tcp:172.30.54.111:10000
set scheduler-locking on

I then `continue` and attempt to break with ctrl-c.  Press ctrl-c again 
to get back to the prompt anyways and try `interrupt`.  I have 
additionally tried forcing the interrupt sequence trying each of these 
in individual sessions entered before the above ‘script’.

set remote interrupt-sequence BREAK
set remote interrupt-sequence BREAK-g
set remote interrupt-sequence Ctrl-C

I have not noticed any difference between them.  I have also tried just 
leaving it at default (ctrl-c).

Any recommendations on how to proceed?  Is it expected that I must 
interrupt the program from outside of GDB when remote debugging with 
gdbserver?

Thanks for any help you can provide.

Cheers,
-kyle