gutsy: nvidia kernel module version mismatch after update

[^rooker]

[PROBLEM]
Trying to start my xserver (with the restricted nvidia driver), I got the following error:

Error: API mismatch: the NVIDIA kernel module has the version 1.0-7184, but this X module has the version 1.0-9639. Please make sure that the kernel module and all NVIDIA driver compontens have the same version.

For sake of completeness (and findability for others), here's also what my "dmesg" output said:

NVRM: RM/client version mismatch!!
NVRM: aborting to avoid catastrophe!

[SUSPICION]
I suspect, that I've booted an older kernel than the most recent one installed on my system - but it should take the modules from the right directory for *that* kernel.
Gotta check.