What is your console's model? Do you hear any odd sounds (Clicking, scrapping etc)?
I presume that you're using the last version of ESR that was publicly available.
Try discs of better quality (E.g. Verbatim DataLife Plus DVD-Rs). Some older consoles have problems reading Memorex discs.
Even if your console doesn't have issues reading Memorex discs... it may be actually wearing out your laser quicker than you think (Unless your console is a modern slimline without all the crap laser issues).
Unmodified SCPH-77006 with SM 3.6
SCPH-39006 with M-chip modchip, SCPH-10281 NA and refurb Seagate 80GB HDD
SCPH-10000 v1.00 with SCPH-10190 PCMCIA NA and SCPH-20400 HDD unit