there doesnt seem to be a problem with the buildcraft version i think it was just the way TEKKIT rushed out a newer version <object class="emojione" data="https://resources.enjin.com/1489581540/themes/core/images/emojione/svg/2639.svg?0" type="image/svg+xml" standby=":(">:(</object>
bearing in mind buildcraft for 1.2.5 (tekkit) is version 2.-.-.- , where as FTB buildcraft is version 3.-..-.- ......
so the bugs in tekkit version should be not be there in FTB version <object class="emojione" data="https://resources.enjin.com/1489581540/themes/core/images/emojione/svg/1f642.svg?0" type="image/svg+xml" standby=":)">:)</object>
bearing in mind buildcraft for 1.2.5 (tekkit) is version 2.-.-.- , where as FTB buildcraft is version 3.-..-.- ......
so the bugs in tekkit version should be not be there in FTB version <object class="emojione" data="https://resources.enjin.com/1489581540/themes/core/images/emojione/svg/1f642.svg?0" type="image/svg+xml" standby=":)">:)</object>