I would ask you for this question
Model number : WS-C2960G-48TC-L
Please find here below my answers to your questions :
1) All I know is that the customer is pooling this MIB (126.96.36.199.188.8.131.52.276.1.4) in command line, from a unix station. But, here in our lab, we tried the same thing, using Snmpwalk and it’s not working (NULL value) . For all the others MIB we have tested, it worked fine.
2) This was tested with the 12.2(44)SE and 12.2(52)SE who are supposed to support this MIB.
3) From what I know, there are no issues with other OIDs.