Samsung has suspended a software update that upgraded UK-based Galaxy S3 owners to version 4.3 of the Android operating system - also known as Jelly Bean.
The download first became available about a fortnight ago, but subsequently some users began complaining of numerous problems.
These included faster than normal battery drain, some apps refusing to work and alarms failing to trigger.
The firm said it was now investigating the matter.
"We are committed to providing customers with the best possible mobile experience, and will ensure to resume the upgrading service at the earliest possibility," it added in a statement.