Calc crashing

When moving blocks of numbers from one part of the spreadsheet to another, the Calc file crashes. I have 3 similar Calc files and this only happens in one. 2 of the Calc files are around the same size 3 Mb. This is the error that appears in the system log

.Jan 7 12:38:44 pj-selgbuild kernel: [ 2995.695449] SelectionManage[32697]: segfault at 0 ip 00007fa8d05a9ab2 sp 00007fa8d293a900 error 4 in libsclo.so[7fa8d02de000+c7d000] Jan 7 12:39:24 pj-selgbuild kernel: [ 3036.343210] [UFW BLOCK] IN=eth0 OUT= MAC=01:00:5e:00:00:01:00:22:75:c3:4c:85:08:00 SRC=10.1.1.1 DST=224.0.0.1 LEN=28 TOS=0x00 PREC=0x00 TTL=1 ID=48312 PROTO=2 Jan 7 12:39:24 pj-selgbuild kernel: [ 3036.493305] [UFW BLOCK] IN=eth0 OUT= MAC=01:00:5e:00:00:fb:e4:f4:c6:00:e7:be:08:00 SRC=10.1.1.2 DST=224.0.0.251 LEN=32 TOS=0x00 PREC=0xC0 TTL=1 ID=0 DF PROTO=2 Jan 7 12:39:27 pj-selgbuild kernel: [ 3039.170720] [UFW BLOCK] IN=eth0 OUT= MAC=01:00:5e:00:00:fb:78:92:9c:75:d2:3e:08:00 SRC=10.1.1.7 DST=224.0.0.251 LEN=32 TOS=0x00 PREC=0xC0 TTL=1 ID=0 DF PROTO=2 Jan 7 12:40:04 pj-selgbuild kernel: [ 3075.875658] [UFW BLOCK] IN=eth0 OUT= MAC=01:00:5e:00:00:01:00:22:75:c3:4c:85:08:00 SRC=10.1.1.1 DST=224.0.0.1 LEN=28 TOS=0x00 PREC=0x00 TTL=1 ID=48313 PROTO=2 Jan 7 12:40:07 pj-selgbuild kernel: [ 3079.522791] [UFW BLOCK] IN=eth0 OUT= MAC=01:00:5e:00:00:fb:78:92:9c:75:d2:3e:08:00 SRC=10.1.1.7 DST=224.0.0.251 LEN=32 TOS=0x00 PREC=0xC0 TTL=1 ID=0 DF PROTO=2

Which distro, distro version and LO version ?

Ubuntu 14.10,
LO Version: 4.3.3.2
Build ID: 430m0(Build:2)
It has just happened again and this is the log
Jan 28 13:26:47 pj-selgbuild kernel: [ 235.075176] soffice.bin[9710]: segfault at 0 ip 00007f05e442aab2 sp 00007fff44b8e840 error 4 in libsclo.so[7f05e415f000+c7d000]

Hi, perhaps you would consider filing a bug report about this crash? You can do this at: https://bugs.documentfoundation.org/. You will need to create a new account there, and they may wish you to make further attempts at debugging and to take a look at the spreadsheet that is causing problems.
You can install the LibreOffice debugging symbols from Ubuntu’s repository.
Cheers.