Innerspace on two PCs stops passing keystrokes after a few minutes of play

Hi, I am boxing EQ2 and recently started encountering issues where my main computer seems to stop passing keystrokes to my laptop, where I run my slaves. I am using ISboxer, the game windows launch correctly, and I am able to play for 10-30 minutes, when suddenly slaves stop receiving keystrokes. If I relaunch my team via Innerspace shortcut, only main PC's window reloads, and none of laptop's. However, if I do "export to innerspace on all computers" from ISboxer, all the game windows on both PCs reload, but keys are still not being passed to slaves on laptop. I tried to shutdown innerspace, and removed the process from tthe list via Ctrl-Alt-Del, and sometimes by relaunching Innerspace I get the correct reload and I am able to play again, but the issue repeats again in a short time. I was boxing WoW too and there was no such thing.

Any hints as to how to avoid this problem? Is it specific to EQ2?

thanks

Alex