printf vs. printk (on LPC32XX)

[SAeeD]

Hello everyone,

I'm getting some weird problems when running tmtests on PhyCORE LPC3250.
I've configured rtems4.10.2 as follows:

$ mkdir b-lpc3250-phycore
$ cd b-lpc3250-phycore
$ ../configure --target=arm-rtems4.10
--enable-rtemsbsp=lpc32xx_phycore --enable-tests=yes
--enable-networking --enable-posix --prefix=$PWD/bsp-install
$ make all install

When I run tmtests, specifically talking, tm01 on PhyCORE LPC3250,
everything works smoothly and all texts are printed on the console.
But when I run, tm03, it hangs in the middle of printing jobs.
When I changed the definition of put_time in timesys.h to use printk
instead of printf, tmtests are working without any problem. That is,
those lines that were printed incompletely when using printf, are now
printed completely using printk.
I must mention that everything works fine with rtems4.11. (Without any
modification.)

I want to ask: what's the point indeed?

Thanks,
SAeeD