[XPERIA X1 General] chicus_bar:
these are my thoughts on the subject....

there are three places on which the case is more likely to crack:

> near the volume button;

> between the off button and the camera;

> on the stylus corner;

and the main quoted reasons for that are:

> heating cycles (#825);

> impact on sliding (#909);

> tension caused by spring force over battery (#846);

> pressure caused by battery cover on removing/ replacing it (#841);

associated with:

> designs flaws: too little material on critical spots (tension concentration);

> inferior quality material.

the way i see this issue, there are different reasons for different crack spots...

> for the VOLUME BUTTON crack, the spring forces and the battery cover are my candidates... the forces over the non smooth-geometry (which leads to tension concentration) with small cross-section (lack of material) makes tension become very high, making this the weakest spot of the case... for this, i did the spring force relief as suggested by (#846)....

also, i noted that the cover was not following the line of the plastic part, so i figured it out that this could be pushing the battery housing... it may explain also why some people had so many (this fellow #863 had no less than 5!!) cracked cases (probably nothing was done about the cover!)... or even breaking on first handlings....

so i twisted the alluminum cover until all the plastic-metal transitions were alligned, bending the battery cover a little bit (increasing the angle), in order to and relief the lateral pressure over the case.. i also try not to remove the cover unless it is strictly necessary...

> for the between POWER BUTTON and camera crack, impact of the opening sliding movement may be the main reason.... the plastic seems to be very hard (perhaps on purpose, because it would be less susceptible to scratches... anyone tried to scratch to plastic?), and as a consequence, more fragile... and the crack appears on the transversal direction of the impact, as it would be expected... also, there is this case of two broken phones (#791) of different people who gives the same use for it (probably a hard use on the keyboard, might it be?)... for this, i try to slide the phone as smoother as i can (more attention on opening, it's harder to cushion the impact)...

> now on the STYLUS CORNER, i guess it have something to do with the stylus handling.... of course, once again, the tension concentration with little material is behind... as with the sliding issue, the only way to avoid it is cautiously handle the stylus... if one takes a look at the first picture posted on this thread, one will see that the more external side of the sylus housing is worn out, what makes one think about the stylus handling... at all, i'm not saying that is user fault... this phone should not have been desinged for the handling cautious little soft handed girls only... as it unfortunatly seems to be...

the heating cycles may be turning the already fragile material worst over time, but i wouldn't bet all my chips on it, only if the material is specially prone to suffer from temperature variations... but with this big series of design flaws, one more wouldn't be all that strange... :)

so i guess that's it... it seems SE putted very tight design specifications (i mean, "this phone should not be bigger than this, no matter what!!!") and HTC designers (mainly, and part providers perhaps possible) weren't capable to make it straight... (specially the bending machine of the battery cover provider :) )... at the better case, lack of costumer(SE)-provider(HTC) communication... at the worst, as some mentioned before, sabotaging (sincerely, i wouldn't bet on this)... SE should have recognized the issue early as the cases of cracked phones started to pop up.... and improved the phone design and/or the production processes, or changed the providers (or taked legal actions over HTC to make it).... and should have done a recall.... now with the **** already spreaded all over, the only thing left for SE would be to treat they (once) faithful clients very well.... but not even this has been done the right way, as it seems...

well, i have a 09w02 x1a, one month of cautious use (specialy with the stylus handling, sliding and removing battery cover), transport on pockets without special case, one one-meter-high fall on a hard floor (thanks god my phone still working!), and no cracks so far... and have a little (little) hope of not having any cracks on the next six months.... or until i get really tired of windows mobile at least :) and for SE, what a tast of a headache it should be....

i would like to thank all the people from xda, they've made this a really fine place... and ask forgiveness for my english... :)