Error when adding a foreign key constraint

[Steffan Sørenes]

I have this table:

CREATE TABLE gene (
gid SMALLINT NOT NULL AUTO_INCREMENT,
gene_if VARCHAR(9) NOT NULL,
chr TINYINT NOT NULL,
models TINYINT NOT NULL,
solub VARCHAR(30),
pts VARCHAR(30),
variant_align VARCHAR(30),
update_tair VARCHAR(6) NOT NULL DEFAULT 'TAIR8',
date_update_araperox TIMESTAMP,
PRIMARY KEY (gid),
UNIQUE (gene_if)
);

an this:

CREATE TABLE model (
gid SMALLINT NOT NULL,
mid TINYINT NOT NULL,
primacronym VARCHAR(20),
primfullname VARCHAR(50),
description TEXT,
model_type VARCHAR(20),
PRIMARY KEY (gid, mid),
FOREIGN KEY (gid) REFERENCES gene(gid)
);

It works fine to create these tables. But when I try to create the table below i receive this error: ERROR 1005 (HY000): Can't create table './db_steffans/modeldata.frm' (errno: 150)

CREATE TABLE modeldata (
gid SMALLINT NOT NULL,
mid TINYINT NOT NULL,
size_bp SMALLINT,
size_aa SMALLINT,
model VARCHAR(20),
brief_description TINYTEXT,
extended_description TEXT,
swiss_protid VARCHAR(8),
mw VARCHAR(8),
pi VARCHAR(8),
protein_seqs VARCHAR(40),
nucl_seqs VARCHAR(40),
PRIMARY KEY (gid, mid),
FOREIGN KEY (gid) REFERENCES gene(gid),
FOREIGN KEY (mid) REFERENCES model(mid)
);

I tried to create the table without Foreign keys and it worked. So i tried to add FOREIGN KEY (gid) REFERENCES gene(gid) manually with alter table and it worked, but when i tried to add FOREIGN KEY (mid) REFERENCES model(mid) the same error appear: ERROR 1005 (HY000): Can't create table './db_steffans/#sql-db5_e57e8.frm' (errno: 150)

What is wrong? All tables use INNODB.