1997 Corsa 1.4 LS?

In my car I have a cassette player/radio, I find that when I listen to it, the next time I start my car it struggles to start or sometimes doesn't even start until I've tried about 4-5 times then it really struggles but once its started it runs fine.
Due to this I haven't listened to the radio or plugged my ipod in for a few months. I'm wondering if anyone else has ever had the same problem or if anybody knows what is causing this. It may not be anything to do with it but I recently found that the battery was very low on acid and it was for some time but it has been refilled.

I've been told by a few friends it could be a number of things but I'm no mechanic and I don't really want to be taking to the garage for them to say its something different and to pay for it when it doesn't even get fixed as driving without music is becoming really boring.

Thanks for reading and hopefully someone has a solution.