How do I setup SPA5xx phones to navigate through service menus?

[iksi2010iksi]

I'm sort of lost.

I've got some SPA5xx phones working on a Fritzbox 7270. So far I got erverything running fine except one major problem: Once I have initiated a call to a e.g. service hotline which wants me to select the appropriate contents by dialing a number, I can't do so. Well, I can very well dial, and I get the sound of the key pressed, but the automtic menu system of the service hotline won't recognize the dialed number.

I hope I could make my question clear, since I'm not a native English speaker.

I went through tons of forum questions but just cannot find a solution.

Anybody can help me?

[atcomputing]

I once had the same problem with a SPA942 and it was solved by the remote end telephone service provider.

[iksi2010iksi]

I was able to fix the problem by myself. I had to change the DTMF Tx method ("Inband & Info" would do it in my case). Now everything is working fine.