Songs all disappeared

After noon all,

Switched on iTunes Match before I left work and downloaded Sheryl Crow's Globe Sessions before I left. Switched off Match when I left too.

Problem is I am now left with just that album on my phone and the rest of the tunes (about 8gb) have all been wiped.

It happened a couple of weeks ago and I had to load all the songs back on again over the weekend, as I will have to again this weekend.

Any ideas?

lm2