And which page is this on? Have you tried multiple different pages? (index, showthread, forumdisplay etc)
271 queries is NOT right, and neither is 54.75MB memory usage. For reference, here's what I get on the index page on this forum:
Quote:Generated in 0.0226071 seconds (89.64% PHP / 10.36% MySQL)
SQL Queries: 8 / Global Parsing Time: 0.0059030 / Memory Usage: 2.75 MB
Check your plugins - there's probably something causing all that load. The "advanced details" link may be of use for tracking down queries.
XThreads adding 40MB is also unusual, but it's possible that its memory usage correlates with other plugins, so I'd check your other plugins first.