MSmerge_tombstone Growing And Growing

I have merge replication setup up for 6 SQLCE Subscribers.
I have noticed that the MSmerge_tombstone table is growing
at a fast rate regardless of any changes to the data in
the database. It seems to be consistantly adding 50 rows
of data to the table every 2 minutes. As the table grows
it causes the SQLCE subscirbers to fail with the following
message:

ERROR: -2147467259
SQL Server Reconciler failed: Run

ERROR: -2147200925
: Failed to enumerate changes in the filtered
articles.

ERROR: 0
: {call sp_MSsetupbelongs
(?,?,?,?,?,0,?,?,1,?,?,?,?,?,?)}

ERROR: 0
: The merge process timed out while executing a
query. Reconfigure the QueryTimeout parameter and retry
the operation.

I'm sure that this is due to the size of the
MSmerge_tombstone.

Should the MSmerge_tombstone table grow at this rate?
36,000 rows every 24hrs!

I understand there is the sp_mergecleanupmetadata Stored
procedure but if i use this does that mean that because i
have to reinitialise all the subscribers, they are going
to have to pull down the whole subscription again.

I have since Changed a settings to make subscription
expiration date to 8 days instead of never expires but
we're still getting 50 rows added every 2 minutes

SQL SERVER 2000 SP3
Hope someone can shed some light on this for me.

Thanks.
.