What might have caused this puncture?

[nickyboy]

Been riding on the same tubes and tyres for about 6 months, no problems at all.
Went to get the bike out a couple of days ago and found the front tyre flat. I checked the tyre (Hutchinson Equinox) and there were no cuts or damage. So I pumped it back up to full pressure, went away. When I came back it was fine.
So I went out for a ride today. After a couple of hours I could feel that the front tyre was a touch soft and after I got home it felt a bit softer again. I took the tyre off and I found a small hole in the tube. But the hole was on the "inside", where the tube makes contact with the rim tape. The rim tape is absolutely fine. Presumably the contact between the tube and the rim tape was fairly airtight and this was helping to retain pressure.
Could this just be some degradation in the tube over time? Or is there something I haven't thought about that might mean I get a repeat?

 

[fossyant]

Could be a sharp edge on the rim or at a spoke hole. Remove tyre and check rim and rim tape

 

[nickyboy]

Could be a sharp edge on the rim or at a spoke hole. Remove tyre and check rim and rim tape

The rim tape seemed intact and smooth but you've got me a bit worried now. The Equinox was a bit of a bugger to get back on, not looking forward to taking it off again

 

[fossyant]

I fitted new wheels recently, but used old rim tape. Got two punctures in same spot rim side, so removed tyre and tape and fitted new tape. No problems.

 

[400bhp]

As Fossy says. I had some right problems with a small hole in the rim tape and a bike I took abroad.