Cracks in endcaps...and more

[Tin Lizzy]

We have an 89 Limited that we purchased a year and a half ago...Since then (since we picked it up for our first camping trip this year) we noticed a few issues with the end caps...We started to get cracks...IN the front end cap, in the upper left corner there are "two" cracks which have 'shifted' the wood shelf. I can literally put my hand under it andpush it up to some degree as the pastic above is not holding the overhead cabinet in place. Also in the rear endcap of the trailer there are two cracks starting from the rivets which fasten it to the ceiling working back towards the windows approximately 6" long...I have drilled tiny holes to try and prevent them from spreading further...We were camping last weekend, and again the past weekend. In the one week timespan the most unusual thing happened. In our rear endcap adjacent to one of the cracks I noticed the flat portion of the endcap on the ceiling portion of the endcap has bowed inwards. (by inwards I mean a large bow towards the interior space of the trailer). I noticed it when I was laying down and then could feel it with my hand - it is a larger circle about 8-10" in wide...I gently pushed on it to see if it would flex back in but it wouldn't. I have tried to find some info on it in the search but I have yet to see anything even remotely close to this topic. What could be causing these sudden cracks and the buldge in the end cap? The only thing I can think of is the cold climate here makes everthing brittle in the winter and any settling in the cold, etc. causes this??? Also we have our trailer at a lakelot that is a recent development and I am not too sure if the lots are 'settled' properly casuing the trailer to settle differentially. When we get out the level all appears okay in all directions...I don't get it...How can someone own it for that long (17 years) and leave it in perfect condition, then we amass all of these cracks since owning it....Hmmmm