So here is the answer for tech. support on this issue:
"Products: DCS-2132L
After investigating the issue further, we also noticed that there is gaps. Speaking with our engineers, this is normal behaviour. When uploading to an FTP server, the camera will store the video in its internal memory until it reaches the threshold specified in the camera (in your case 30 seconds). Once that threshold is met, the camera will then start offloading the video to the FTP server. During the offload period, the camera cannot continue recording.
So knowing this, the length of the gaps between recording and uploading will vary depending on the video settings (Frame Rate and bit rate) and the Upload/download speed of the source and destination.
In order to fully record (without gaps), your best option would be to use the D-ViewCam, which is D-Link free video management software. Here you can configure recording to a local drive using any criteria you want. You can download the D-ViewCam software from the following link ftp://ftp.dlink.ca/SOFTWARE/D-VIEWCAM/D-VIEWCAM_SOFTWARE_3.60_DEVICEPACK1.5.3.ZIP"
So what I originally surmised that the gaps are caused by the time it takes to transmit the file were correct. It has nothing to do with the delay parameter. I have taken one of mine off wireless and hard wired it, the gaps dropped in half. I use these corporately as well with fast centralized servers and the gaps are very small because it only takes a second to store. It's when I use net based FTP which is a considerable amount slower that I get 20-30 second gaps because it takes that long to transmit the file.