Problem with cassette player that feeds into Audacity

[clashbore18@...]

Problem with it is it keeps flipping sides at the start of the tape and sometimes about halfway through ! Is it cos the tapes have tightened up over the years and the player thinks the tape has ended ? Or something else ? Its a real pain and stopping me from ripping them at the moment. I've googled the problem but there's nothing on it. Seems like a fairly basic piece of kit.