Wouldn't worry too much, its only been 3 starts. After 3 starts last year he had issued 9 walks in 16.2 IP and also had a 5.94 ERA, this year its 8 walks in 15.1 IP. His ERA is a bit higher this year, but he's always been pretty bad out of the gates to the start of the season the last couple seasons. 5.94 ERA after 3 starts in 2011, 6.20 ERA after 4 starts in 2010.
People may say he's giving up more HRs in Cincy but so far he's only allowed 2 HRs, 1 in Cincy (in 1 start there) but in 2011 after 3 starts he had allowed 5 HRs already, 4 of those HRs at Petco Park, but still ended up only allowing 16 HRs for the season.
He's getting somewhat unlucky and also not doing himself many favors either by typically starting off slow like he does. Just takes him a while to get into a groove apparently. I think its most of these factors rather than the ballpark that are killing him and look for him to get better as the weather warms up.
"Chuck Norris has been known to throw a baseball 100 mph. I've been known to throw Chuck Norris 100 mph." - Brian Wilson