5975C Smart card issues

Wondering if anyone has this same problem.  We have a 5975C that will occasionally randomly cause one of the target ions we are looking for to "disappear".  For a target peak the secondary and tertiary ions are present and fine but the primary looks like a "carrot" and/or baselines several times during the peak elution window.  In the past I have replaced the smart card with the thoughts that the signal is dropping or corrupt.  This will solve the problem but it seems to reoccur after 6months to a year.