Marcus -
We are currently going through the same or similar problem
at a client site. The network OS is NT4 SP4, the stations are Win95.
The application runs in VFP6 on the central LAN and was distributed to RAS sites in VFP5. It has been functioning fine for over a year. The intermittent 1104 error started on the LAN and was reported approx a month ago( error logs show it started in May). The frequency of the error increased to the point that the application became unusable - but not on all of the stations. Of six on the LAN, three were seriously effected, one experienced the problem for a few days,
and two(laptops) are uneffected to this point. Last week some of the RAS systems( 3 of 10) started to report problems. Although the reason has not yet been identified,there may be a clue in that the three workstations on the LAN were replaced with new hardware ( same cables) and the problem has disappeared for those users.

We are still investigating the cause, but currently suspect the nic cards( the hardware that was replaced is same vendor,purchased approx the same time, and we are trying to confirm if all have same nic card type/batch) or the existence of a damaged or otherwise errant file that these systems may have in common. We are gathering info on the remote site hardware as well.

We'll be happy to keep you posted if you'd like.

Eleanor