Download counter stops before midway

The window that is shown whenever there is an update available contains a button to download and install this update. When pressed there is a counter showing the number of bytes downloaded. Since (quite) a while that counter stops along the way. Just now it went until a little above the 6MB of a 20+ MB download. It's only the counter, as after a couple of seconds the update is apparently downloaded as installation begins. It is not a very important issue, but the first couple of times you are fooled in thinking the download has stalled...

I checked the source code, but cannot find anything that would cause this behaviour. Other than that, for some reason, GetTickCount does not play nice and suddenly starts to give incorrect (ie. lower than before) results. Now although that is possible after 49,7 days of uptime, that is neither the case here, nor would it be every time an update arrives...

I highly guess that is due to the main process being busy with background things, and does not care for updating GUI parts. I would have to source the process out to a background thread, but I don't feel it's worth it here. The fact that this started recently could be because I disabled UPX compression of the executable. They were around half of the size they are now, so the download takes longer now.

That might be it, however I usually update immediately after starting, so there is not much the main process should be doing ;-). It might be an idea to skip the progress indicator alltogether and just report "Downloading XX MB"? It avoids the idea of a stalled download.