Launch error message on initial attempts home folder

[titus]

Hello,
I'm sure that this problem will have appeared somewhere else in the forum but I can't seem to find the right words to locate it.
Running LMDE Xfce, excellent, runs like clockwork but, all of a sudden, when I first double click or right click> open on my home folder icon (or the file system icon) nothing happens for approx 20 secs and then an error warning appears. The warning is followed immediately by the requested action such that the opened folder overlays the warning. This happens when I initially try to open the folder, if I then go away and work elsewhere, say, reading mail and then return to try to open the folder, it works instantly!
I know someone will say "Just stop moaning and wait the 20 seconds when you first boot up" but I'm concerned that there is an underlying problem which may get worse.
Any help much appreciated, as usual.