cudaError 30 (unknown error)...

[LinuxETC]

Started receiving the following error messages after 12-18 hours of running CUDAminer on x6 MSI 750Ti's:

<time, date, and system stamp removed> GPU #2: cudaError 30 (unknown error) calling 'cudaStreamQuery(context_streams[stream][thr_id])' (salsa_kernel.cu line 958)
<time, date, and system stamp removed> GPU #2: cudaError 30 (unknown error) calling 'cudaStreamWaitEvent(context_streams[stream][thr_id], context_serialize[(stream+1)&1][thr_id], 0)' (salsa_kernel.cu line 946)
<time, date, and system stamp removed> GPU #2: cudaError 30 (unknown error) calling 'cudaMemcpyAsync(hash, context_hash[stream][thr_id], mem_size, cudaMemcpyDeviceToHost, context_streams[stream][thr_id])' (sha256.cu line 446)
<time, date, and system stamp removed> GPU #2: cudaError 30 (unknown error) calling 'cudaEventRecord(context_serialize[stream][thr_id], context_streams[stream][thr_id])' (salsa_kernel.cu line 952)

The cudaminer.conf file is as follows (mining pool details removed):

{
"url" : "stratum+tcp://someLTCpool:3334",
"user" : "someuser",
"pass" : "x",
"launch-config" : "T5x24",
"interactive" : "0",
"syslog" : true,

"scantime" : "10",
"algo" : "scrypt",
"hash-parallel" : "2",
"single-memory" : "2"
}

Host system is Ubuntu 13.10, 64-bit. Feel free to advise accordingly and request further input since this is being captured by syslog as well.