Krisgel,
What do you mean when you say "the cart mistracks"? Is it jumping out of the groove? Staying in the grove but audibly losing groovewall contact? Maintaining groovewall contact but distorting? Does this happen on all records or just some? With all cartridges? Only a few? Just one? Has your setup always done this or is this a new phenomenon?
People are answering without sufficient information as to what's actually happening. As Sherlock Holmes repeatedly reminded Watson:
It is a capital mistake to theorize before you have all the evidence. It biases the judgment.
'A Study in Scarlet', Part 1, chap. 3
It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.
'A Scandal in Bohemia'