Hi Bangra,
Strictly speaking, I'm pretty sure that it is best not to not re-freeze ANY food that has been previously frozen and fully thawed (outside of a fridge)....unless if was raw and subseqeuntly fully cooked. This goes for curry base too. Not only does the quality of the food deteriorate, but, more importantly, there is an increased health risk due to increased bacterial growth in the food.
Having said that, I do it all the time with curry base, as you describe, and so far I'm all right Jack...honest!

Well, probably like you, I aint gonna waste a perfectly good curry now, am I!

Regards,