It seems that the function name symbols in libcublas have changed from CUDA 3.2 to CUDA 4.0:
$ nm -D libcublas.so.3.2.16 |grep cublas
000000000002b250 T cublasAlloc
0000000000095930 T cublasCaxpy
0000000000096730 T cublasCcopy
0000000000097680 T cublasCdotc
0000000000098b70 T cublasCdotu
000000000003cc80 T cublasCgbmv
...
$ nm -D libcublas.so.4.0.17 |grep cublas
000000000002c280 T cublasCaxpy_v2
000000000002f480 T cublasCcopy_v2
0000000000023ef0 T cublasCdotc_v2
0000000000023ee0 T cublasCdotu_v2
0000000000048840 T cublasCgbmv_v2
...
Does anyone know why this was done? I encountered it when loading cublas functions into Python with ctypes.