Apple is investigating graphics glitches affecting its latest laptops, reports claim.
MacBook and MacBook Pro owners have been complaining of unacceptable graphics performance on their machines on Apple's own discussion forums.
They have been enduring unusual visual corruption, in which text appears to have been duplicated, documents fail to scroll or videos appear to flicker.
Some reports claim the problems are resolved in the latest Mac OS X 10.5.3 software, but that is only currently being circulated among developers for testing.
Apple has begun contacting users who have complained of the problem, sending an email which is alleged to state: "Apple has received reports similar to the behaviour you are describing and we are investigating those reports. Further information will come in the form of a Knowledge Base article, Software Update, or Software Release."
Multiple reports suggest the problem is software rather than hardware based, with pressure mounting on the manufacturer to expedite a fix for the problems.