Had a few problems while roaming in Tenerife. The excellent roaming through Movistar suddenly stopped and I lost my signal. I did a network search and set it to automatic. This connected me to Yoigo and I have had no problems except for dialling the answerphone. 555 wouldn't work so I used +44 7870 020555 and this was fine.
However I was still wondering why Movistar would not accept my roaming and then I came across this in a local Tenerife forum.
"Movistar no longer working with EE and not recommended with Yoigo..
I've just got off the phone to EE as I have had problems making calls today and with data. My phone was connected to the Movistar network here and from yesterday Yoigo..
Apparently, they have fallen out commercially and Movistar will no longer support EE network traffic. EE are recommending that anyone in the Spanish area connects manually to the Orange network as Yoigo doesn't have a full agreement with them either, so you may experience problems.
Hope that helps anyone who is wondering why their phone isn't working properly."