Hi,

I've had my FF400 for about 10 years now (rough estimate).  Since a week or two i've been experiencing glitches / dropouts. They occur at irregular time intervals, but roughly said about once every 5 to 10 minutes. The sound gives a short 'crack' and drops out for about half a second, after which everything goes back to normal behavior.

The FF400 has always been hooked up to the same desktop pc and I haven't added any new peripheral gear or software/drivers that could cause the problem.

The issue is not related to recording / writing audio to hard drive, it also happens when simply monitoring audio.

It happens in any DAW and also outside the DAW when simply listening to incoming sound.

I've hooked up different sound sources to exclude the possibility of the audio source and specific input as the cause. 

The glitches also occur when playing back audio files from my hard drive, so I suppose this rules out AD conversion as the cause

I have hooked up the FF400 to 2 entirely different firewire cards in my pc (one has VIA chipset and the other Texas Instruments). I have also tried different firewire drivers.

I have tried both externally and bus-powered.

I have run Latencymon to see if any spikes that could compromise the audio stream, but it doesn't report any issues. 

I am running Win 7 pro x64. After the problem arose, I updated to the last available (essential) updates.

The RME FF400 driver is also updated to the latest version.

I can't think of any more things to try at this point, any input would be very welcome