some question about SavePoint ?

Hi,

I have a question about psqlodbc .

After I execute a SQL , I want to ignore some error ,and continue to
execute my SQL.but I will get some error like that :

"current transaction is aborted, commands ignored until end of
transaction block"

I try to use SavePoint to solve this trouble , but I got some problem .
example:
.....
1. set SQL_AUTOCOMMIT_OFF
2. SQLConnect()
..............
3. SQLExecDirect() -> SavePoint sp ;
4. SQLExecDirect() -> insert into test values(...) ;
5. SQLExecDirect() -> Release SavePoint sp;
6. SQLEndTran() -> commit ;
7. SQLExecDirect() -> SavePoint sp ;
^^^^^^^^^^^^^^^^
8. SQLExecDirect() -> update test;
.............

Until 6, it return OK, but at 7 , it will return some error like

"SAVEPOINT may only be used in transaction blocks"

so , I have to use "begin" to start another transaction after I execute
the "commit" at 6 ?
Why can I use savepoint at 3 without execute any "begin" ???
Or I have some mistake ?
My psqlodbc version is 8.01.01.02(Unicode)

And, I have to use SavePoint to rollback to current SQL?
Don't I have another way in psqlodbc ?

Regards, Zhao.