ArcSDE C-API SE_stream_calculate_table_statistics() crash with Oracle

I'm maintaing an ArcSDE client application which apparently was working with ArcSDE 9.1

Current configuration: ArcSDE 10.1 with Oracle 10.1, Win 7 x32/x64

Symptoms when calling SE_stream_calculate_table_statistics() with SE_DISTINCT_STATS as mask on a STRING property:

1. crashes with SE_NET_FAILURE (-10)
2. memory violation when using direct connect in sdeora11gsrvr101.dll
3. Works fine with numerial properties (integer/double)
4. Works fine with SqlServer with any property type (integer/double/string)

Note: 2) and 3) prove the code is correct.

Any information greatly appreciated. Thanks in advance.