"java -X" messages are localized in JDK7(GA).
The explanation of -Xmx is incorrect.

Original English message is
 "-Xmx<size> set maximum Java heap size",

but localized Japanese message is
 "-Xmx<size> Java no saishou hihpusaizu wo settei suru”

This means "set minimum Java heap size" in English(totally opposite meanings).

The above Japanese message must be
 "-Xmx<size> Java no saidai hihpusaizu wo settei suru”

REPRODUCE:
Launch "java -X" in JDK7

FREQUENCY:
This problem always occurs.