Bug: when a ship is partially constructed in shipyard and awaiting more blocks, leaving the sector causes the ship to unbuild and return to loaded state, and the blocks to be forever lost.
Steps to reproduce:
1.) build shipyard and ensure adequate space in shipyard computer inventory
2.) load blueprint of ship and put in some of the blocks needed for construction
3.) start construction and verify ship is partly built in shipyard
4.) get into a different ship outside the shipyard which has a jump drive
5.) jump to a sector far enough away to unload the shipyard from currently active memory
6.) jump back to shipyard sector
7.) investigate shipyard: ship hologram will be present in hangar with no blocks built
8.) investigate shipyard computer: in blueprint loaded state, awaiting construction order and none of the blocks have been returned to inventory nor any connected chests
I did experience this bug the same way when trying to build the same ship again with a new load of parts, however when trying a different and much smaller ship design which I had deconstructed to blueprint in the same shipyard, the results were slightly different:
1.) the partially built ship was invisible in the shipyard
2.) upon leaving the sector and returning, the shipyard computer was still in during-production status and while the bar showed zero percent completion, adding the remaining materials did allow the ship to be built.
The ship that led to block deletion is available for download from this webpage: http://starmadedock.net/content/caldari-cormorant-standard-edition.3028/
Or you can download the file directly with this link: http://starmadedock.net/content/caldari-cormorant-standard-edition.3028/download?version=3937
The smaller ship that did not lead to block deletion is 15 blocks in mass:
1 ship core
1 power reactor
1 rail docker
1 thruster
6 shield capacitator
4 shield recharger
1 white rod light
Image of the ship here: http://i.imgur.com/KtiiAN8.png