Queue not queueing

Question

I have a producer / consumer architecture - data are being read (from a TCP read) in the producer loop and placed on a queue. The consumer is reading the queue and doing lots of modelling, analysis and display. This architecture was chosen because the data doesn't arrive at a consistent rate from the server - due to network load etc. I am reading 'number of elements on queue' to get a rough idea if there is latency in the system. 
The server sends a frame number, which I save using the TDMS format. I recently noticed that when the number of elements on queue increases, the frame number skips, i.e, when data are buffered on the queue, they don't seem to appear when the elements are dequeued.
What's going on?!
Unfortunately I can't post the code, but I will try and produce a cut down version. 

Answer 1

The queue size is default (unlimited).
The queue builds up when the PCs processing load goes up - when an email arrives etc. You can see this by reducing the delay time right down to 1ms and click "real-time operation" then do something else with the PC - shake the vi window around the desktop for example. The queue should build up, unless you've got a good PC!
The problem I have with my real program is that data being queued are lost.
Other difference with my real program - data are coming from a TCP read function, there is no delay in the producer, the data are text not numerical, and the consumer is huge. I'm not sure how to set a sensible timeout. There's also no handshaking with the server.  
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