The good folk of the south have had a few tremors to deal with of late.

If they thought 50 odd SNP politicians marching on Westminster was an earth-shuddering event then the seismic activity that left tea cups and vases rattling in Kent the other night must have had them chattering away like a collection of novelty wind-up falsers. Across the county border here in leafy Surrey, meanwhile, there were more rumblings to deal with. While Francesco Molinari cemented his position at the top of the leaderboard at the halfway stage of the BMW PGA Championship and finished a shot clear of the field with a 10-under tally of 134, there were some mutterings and mumblings from one or two big hitters about the state of the West course's greens. These are not new grumbles, of course. After a series of withering comments from some of the leading lights a few years ago, the Wentworth top brass decided to rip up all 18 putting surfaces in 2009 and re-lay them. "They were really good for a couple of years after that but they have got worse each year since then," admitted Luke Donald, who won back-to-back PGA titles in 2011 and 2012 and had inched up into the fringes of the top-10 yesterday with a 70 for a 140. "If there was one championship where the greens should be pristine then it's this one. This is our flagship event and they don't putt as good as they should. I think the only way to fix them is to redo them again."

Mild-mannered Donald doesn't do savage blasts. Justin Rose, a man as charming as one of Capability Brown's gardens, is not known for vocal volleys either. Yet the duo's quiet, critical assessments of the putting surfaces will have been ringing in the ears of the Wentworth high command last night. They clearly felt like they were putting on something akin to a cobbled street. "It is disappointing in the sense that the whole reason they changed the greens was that if anyone had a six-foot putt on the last green on Sunday to win they would feel confident about holing it," added Rose, who had a 72 for a 143. "You now can't say for sure that will happen as they are not super true. I had a four-foot putt at the last and it looked easy on the TV, but that was different from the running commentary in my head. You don't trust your read on these greens."

Lots of rain, plenty of golfing traffic - estimated at up to 300 rounds a day - and the time of the year are factors that have not helped the cause. When the greens at Gleneagles came in for criticism in recent years, those in charge forked out £1/2 milllion on a Sub-Air system, an elaborate contraption that sooks moisture out of the putting surfaces. The Wentworth piggy bank might be getting raided. "Every championship course needs Sub-Air because it helps control the environment better," said Rose. "But I'm no greenkeeper."

Of course, for all those left feeling blue on the greens, there were others still in the pink. Molinari recovered from spilling two shots on his first three holes with a haul of birdies including three on his last five holes in a 69 while Byeong Hun An, the former US Amateur champion, emerged late in the evening with a polished 64 to seize second place on his own. Emiliano Grillo took flight with a pair of back-nine eagles as he soared into a share of second with a sparkling seven-under 65. The 22-year-old has now made the cut in his last 18 events, a profitable run stretching back to last September. Having finished sixth and third in his past two tournaments, the upwardly mobile Argentinean has the scent of a maiden victory in his nostrils. "If you keep knocking on the door it will open," said Grillo, who holed a bunker shot from 15 yards for his first eagle on the 12th before flighting a sublime 5-wood to tap-in distance for a three on the par-5 18th. Local lad James Morrison, fresh from winning the Spanish Open last weekend, posted a 66 for a seven-under aggregate, a fine effort given that he was four-over after 11 holes of his first round.

On the home front, Scott Jamieson steered himself in the right direction with a tidy, four-birdie 68 to sit alongside fellow Scot, Marc Warren, on a 142. Warren's wheels began to shoogle with back-to-back double-bogeys at 12 and 13 in an eventful 74. Chris Doak made just his third cut of the season on a 143 after a 71 and was the only other Scot to make it to the weekend on a day when Paul Lawrie withdrew with a groin niggle and Craig Lee retired after two holes.