The big news is that for the first time in two years more surveyors in Britain said prices rose than said they fell, according to the latest RICS housing market survey.

The big question is whether this is the start of a continuous and sustained recovery in the housing market or just, as the ITEM Club suggested yesterday, a false dawn.

The big problem is that while the survey points to a general rise in prices, it also highlights that there are deep fault lines running through the current housing market. And these are creating considerable uncertainty over what meaning to put to the recent rally.

One thing that seems pretty likely is that many of the pet theories put forward by various experts on why house prices are rising despite a still fragile economy and growing unemployment will be put to the test.

Firstly what does the survey say?

It shows for August a positive balance of 10.7% (seasonally adjusted) between those surveyors seeing falling prices and those that have seen prices rising. This is set against - 5 7% in July and the trough of -94.7% when the market was in meltdown in April 2008.

The survey also shows that sales are increasing and stocks are increasing, although not as fast as sales. So the sales to stock ratio (a pretty good basic indicator of future prices) also rose.

Unsurprisingly on the back of this surveyors are increasingly confident of price rises, a confidence that will be bolstered by the increase in new inquiries in August, although the pace of increase was checked on July's high.

And interestingly for the first time since December 2007 there was an increase in people trying to sell their homes.

So taken at a national level what might all this mean?

That very much depends on what you think is driving the market. So let's take the generally accepted view that the rise in prices is in large part down to a shortage of supply, which is helping to prop prices.

The theory is that vendors are under less pressure to sell than might have been expected if interest rates were not at historically low levels. So we have created with this recession the phenomenon of the "reluctant landlord", who is holding onto a property until the market bounces back.

And the facts do seem to fit with the argument. There is limited stock and a rising number of buyers, interest albeit from a very low base. It seems reasonable to assume that these people are gradually bidding up prices.

The unsettling question is what happens when potential vendors mutate into real vendors. Will we see a shift in the demand-supply balance and see a fall in prices.

What is bothering many experts, and certainly the ITEM Club economists, is that the pool of potential buyers is limited, particularly the cash-rich element that has accounted for a far greater proportion of the action recently than they would have in a more normal market.

Will the current price rises and strong sales figures tempt reluctant landlords and a bunch of other want-to sellers to put their properties up for sale? And how much would this boost supply?

The RICS certainly sees signs that more positive "news flows" are encouraging more vendors back into the market. This leaves the big unknown: can the increase in number of buyers keep up with the increase in the number of properties coming onto the market and if not will prices fall?

But, in truth, the market is a bit more complicated than considering averages on a national basis. There are big regional and local differences and within each regional or local area there are various layers of buyers and sellers.

What is very clear from the RICS figures is the pattern of recovery, if that is what it is, is very patchy regionally.

The positive numbers are by and large being generated on the back of a much strengthened London market with strong upward movement in the rest of the south of England and in Scotland.

There is a band across the middle and parts of the north of England that spreads into Wales where house prices are still on average falling, according to the RICS survey.

What the survey does not show is who is buying and who is selling. Are we seeing a return to a fully functioning housing market or are we seeing a return of activity only in a layer of the market where reside the relatively equity rich?

Hopefully the next few months will provide us with more data that may start to answer more of these questions.