Hi,
I'd be more than happy to help. A couple of things that come into my mind.
The OFDM Synchronization block is a combination of our "old" OFDM Symbol acquisition (for a while now it's been part of GNU Radio) and Sync and Channel estimation blocks (which performed equalization and integer frequency correction) . The most important difference is that OFDM Synchronization includes a loop with the estimated channel gains, which in turn is used to estimate the sampling error (plus fine frequency errors). It also indicates some events downstream via tags, just like the older blocks. This new "DVB-T OFDM Synchronization" block should then be a combination, if I'm not mistaken, of OFDM Symbol Acquisition plus Demod Reference Signals (I'm sure Ron will know more on this).
Anyhow, my point is that you should take a look at the OFDM Symbol Acquisition and Demod Reference Signals blocks in GNU Radio, and check which tags are used and when. Maybe this lack of tags is generating an unforeseen situation on the downstream blocks which generate the segfault? Furthermore, if I'm not mistaken, the pilots in DVB-T (in particular continuous pilots) are not exactly the same as in ISDB-T. Another possibility is that the Demod Reference Signals block is not equivalent to our Sync and Channel estimation block, and further processing is needed for it to be ready for the DVB-T Demap...
best
Federico