Transaction not actually commited

I start a trans. I'm adding some userfields in a usertable. no errors. thus, i do in the end:

if (this.company.InTransaction)

this.company.EndTransaction(SAPbobsCOM.BoWfTransOpt.wf_Commit);

i have no error. it's executing the endtransaction.

problem: i do not see anything at all modified in my db (like as all my add/updates to usertables are ignored).

any help?