Strange error message during kernel execution: "No kernel updates in a while..."

ok. I've gone through all my kernels and I cannot see any race condition possibilities.

to make things worse, adding debug code seems to make this error/warning message disappear so I can't even pinpoint the specific kernel(s) causing this.

since I have clFinish right after all kernel submissions I don't think this error/warning is caused by host side kernel ordering/sync problems.

any ideas would be appreciated.