There are some bug fixes with migrating business rules to calc manager in the patches though it is not possible to say whether these will address the problem you are experiencing, the fixes look to be aimed at the functionality side after migrating.
It is probably best to patch 126.96.36.199 anyway as there have been a number of important fixes been addressed.
I would definitely install the patches and try again. I just did one from 9.3.3 to 188.8.131.52 and had several errors and then in between patch .303 came out and did not get the same errors. You should pay attention to all pre-req's and order of the patches.