The OP suggested using a tantalum...you should use tantalum(something about ESR).

Also, definitely include the 0.1uf (ceramic/monolythic), or a couple of them in parallel.

Although the length of the wire(resistance) is a factor, the real problem here would be the inductance of wire. Doubling/triple/quad wiring using CAT5 is part of the fix for a decoupling problem.