We noticed when it rained, water was coming down in sheets from the gutter, not going through the gutter!  We do not have trees around our house, so we knew it wasn't clogged gutters.  Or was it?  We had a couple of companies come by and look, one wanted to replace all our gutters, the other one took pictures and showed us that the gravel from the roof tiles was caked in the gutters, causing them to weigh down and start to pull away from the house.  We asked for a quote, it was very reasonable and soon our gutters were cleaned, reinforced and all the corners and joints resealed.  And we had a new downspout installed.  Very, very pleased!  Here is a before and after picture:

We recommend All Quality Roofing for gutter and roof issues.