As Soddim says, certainly not a 'problem' as such.
Failure to light does occur occasionally, but is more likely than not a quick fix, and usually does tend to be a dirty Hot Shot injector. This is rectified either using a bastardised Landrover speedo cable which is passed through the fuel feed pipe from the ABFCU to the Hot Shot head, to remove the offending carbon.
The alternative 'correct' way, is to use the R-R Hot Shot purge tool. This is a 12" stainless pipe, which connects to the Hot Shot injector itself and is pointed to atmosphere through the open engine door. An EGR is then carried out, which reverse purges the head of the injector. Obviously this is a little more time consuming, but the officially favoured way
As an aside, Reheat lights are usually pretty instantaneous, and can definitely be felt as a light 'thump' commensurate with indication of light up on the Aj gauge.
Flipflopman