I started playing multi table tourneys again about a month ago. The results i had with a new strategy of tighter play had been paying off nicely. My results were as follows:
51/872
8/640
16/480
32/620
I was quite pleased with my play and results. However in the last week or so my results have suffered. I feel i have been playing the same calibur of poker as i was before but im not just not sure. The last 3 tourneys i played i finished
432/ aprox. 1000
186/450
203/415
Is it possible this is just due to not getting the cards or is my game slipping without my notice. Any suggestions on how to correct this slip in results would be great. or just tell me im riding one of the lows and it will pass eventually.

You're goign to need at least 50 more events before you can determine if any of these results may be accurate. The first few event may just be luck, you could be the worst player ever and had just gotten lucky.

There's a huge variance on MTTs.

If you finish outside the money it doesn't matter if you come last or just short of the bubble. What's important is that you play your strategy consistently. A long run of blanks can be followed by a couple of final tables without changing a thing.

I've had a couple of dozen final tables and consider that I am playing the best game I've had at the moment, but I've not got close to the cash in the last dozen MTTs I've played.

You may find it hard to demonstrate conclusively that MTTs are a long term winner for you, or that your skill is a factor. Also, many people consider them a crap shoot compared to Ring games. It's true that poor play can be rewarded in tourneys but I also think that a good player stands to make significant sums if prepared to accept long breaks between huge wins.

So to answer your question, it could be you got lucky or it could be that you are just experiencing normal variance.