I'm having the EXACT same problem: I cannot upload bid changes to my keywords.
When I roll over the keywords with the yellow exclamation point, it says:
"An internal error has occured"
My God, I'm going crazy over this software.
Last week I had to reformat my hard drive and reinstall Windows just to be able to log in!!!
After contacting the support 3 times, they couldn't help me, so I helped myself.
Now, another problem!
Please, Microsoft, please, fix this!