Size of .mat file varies and does not save consistently

Hi All,

I am trying to save the variables in my workspace but some odd things are happening. First when I tried to save it was taking a long time and then when I thought it had saved and I tried to reload the .mat file there was no data, and upon checking it had 1K size. I thought that the very large size (around 7GB) was an issue so altered the analysis to load in only the required data so the size is reduced to 0.03 GB (I am analysing model outputs which are saved very inefficiently as text files and so I load them into matlab arrays for analysis). However, even with this when I save the workspace the space taken up fluctuates from what I expect to much smaller and even 1KB, even after it looks like it has finished saving, alongside regular error tones from my PC. I have tried also saving in version 7.3 but I get the same effect. I am working on a remotely accessed PC into a 2.5TB drive, so storage space should not be an issue. I am using Dropbox to sync across the data, and these files are set to be saved on the hard drive on this PC. I don't know what to do as I cannot be confident that the workspace data has been saved, as in the past I have seen that there is data in the .mat file and cleared the workspace only to find it has 'dissappeared' later and I cannot re-load it. Given that loading all the text files into a matlab format is a slow process it is a pain to repeat!

I would be grateful of any ideas you have to solve this problem.