I originally installed DSM 4.1 from the packages below.
DSM_DS3612xs_2668.pat (83.4 MB)
https://mega.co.nz/#!JF8xxTIC!XxrW-GYDB ... vCLIg7W6x0
SynoBoot_3612xs_4.1++.img (200.0 MB)
https://mega.co.nz/#!4F0S0YQR!eAK8PhgGy ... InCEe0dmVc
I migrated to 4.2 with these packages below.
DS3612xs_3202-Repack.pat (94.3 MB)
https://mega.co.nz/#!AQEAiLRA!RJhGcmBjb ... tTJxb0paNQ
microserver-dsm-4.2.img (123.0 MB)
https://mega.co.nz/#!cIUlkBpJ!EXro9g_hc ... WpBzzGK2_A
I was able to keep all my files except the PEAR installation, but that was not hard to reinstall. I also had to reinstall the Bootstrap as it was deleted with the migration. Everything is up and running on 4.2. (I'm also running a Gigabyte EP45-UD3P Motherboard with Core 2 Duo Processor)