GS running baddle with Mexican fuel - looking for ideas.

[strsout]

I´m i´m in Creel, Mexico, and my bike is running pretty bad.

It´s a 2003 GS 1150.

It dies almost every time it goes to idle. It looks like a bike w/o fuel injection, like the old carb bikes, when the altitude makes difference on the performance. (I´m at about 7.000)
Very odd for a fuel injection bike and since I dont understant much of mechanics I would like to ask for help on this forum.

This is the full report:
Was running fine when using gas 91, first gas was in USA, second was Premium, in Mexico
Then the third gas the 91 was not available, so I have to use the normal one, from a Pemex source (not those that they seel near the roard)
I had about 4 gallons of good stuff, then I fill the not so good stuff (5 more gallons of mixed) (11gallon tank)
After about 70 miles the bike start running baddly.
at every ´tope´ (the mexican speed bumper), the bike almost die when I resume accelaration.

If I resuem gas on any gear, it ´coffs´ baddly and ask for a lower gear.
I have to keep it over 1500rpm or it will die.

I tought I had a bad gas, so I stop after 130 miles and filled up with the good stuff again (91) with about 3.4 more gallons.
Still the same.
I noticed that if I stop the bike for few minutes, then turn on again, it will run fine for about 5 minutes then will start acting funny again.
It has new spark plugs (BMW) and I changed the fuel filter just before this trip.
Any advise?
I´m not sure when I will be able to check it again, but I will try tomorrow.

There is no internet here on my room, so I´using this cafe, that will be closed tomorrow (sunday)

If you happen to be here in Creel, I´m on the Magaritas Hotel, the one on the Cruzeiro street (yes... there are 2 Margaritas Hotel)

Thank you for any ideas.