I dont think size of the file is an issue over here, as the same script is reading and writing to the file perfectly. It is just truncate which throws me this error.
The file is large enough that 32-bit interfaces are going to have trouble. When you call truncate you're hitting a different C function than normal reading/writing hits, and it is seldom used. Is it really beyond the bounds of possibility that this case got missed?
Given that it is easy to test it is at least worth testing the possibility, even if you think the theory is unlikely.