can't update tables with access

Hello NG, 

I works with ACCXP SP2 and as backend with a SAPDB 7.4.3 Build
027-121-048-452 (Linux Suse8.2), SAP-ODBC 7.4.3.  

I linked the tables via ODBC in my access apps. and insert works fine, but
update and delete is not possible, access stop with error: "another user
....".
The problem is, there is not another user! It seems that the record is
locked, with no timeout. 
Have anybody an idea to make a workaround, relock the record, .... ??????

Greeting and thanks Gerard