Modders of Fallout: New Vegas have run into special issues that previous iterations of the construction set didn't have. Those primarily being error reporting. For whatever reason, Obsidian doesn't see fit to enable such things; so if a script fails to compile, it doesn't tell you as much - it simply refuses to save.
We got out around this for months with a utility called the GECK Powerup, or simply GECK-PU. It reenabled the error reporting, fixed some crashes and stability issues, and was an all-round improvement.
Well, we lost the powerup in the transition to GECK v1.3; and still Obsidian couldn't be bothered to enable even error reporting to tell us why the script failed to parse.
I lamented loudly the other day the loss of this utility, as it made the NV-GECK infinitely more bearable to mod with.
Apparently, someone was listening. This morning, there was a new file uploaded to the NVNexus, The GECK 1 3 PowerUp for Fallout New Vegas. If you're a modder for NV, I highly recommend picking it up. I haven't had a chance to test it yet, but I'm not expecting much in the way of issues.